Reboots, rivals and a red state Democrat: Here's the weekly roundup of the 2020 field

The massive field of Democrats vying to unseat President Donald Trump in 2020 swelled this week with two more entries into the field.

On Tuesday, Montana's Steve Bullock, the two-term governor of a state Trump won by 20 percentage points in 2016, announced his candidacy for president, while New York City Mayor Bill de Blasio joined the race on Thursday. But former Vice President Joe Biden continues to lead the pack as the early polling front-runner.

This week candidates also traded barbs over climate change, speculated about which rival would make the best running mate come the general election and reacted to a controversial anti-abortion bill signed into law in Alabama.

Here's the weekly roundup.

May 10-16, 2019

Michael Bennet (D)

Bennet campaigned in Iowa and New Hampshire during the second full week of his presidential campaign and continued to highlight education issues.

"I really worry, as a former school superintendent, that my generation is at risk of being the first generation of Americans to leave less opportunities to the people coming after us," Bennet said at a campaign stop in Bedford, New Hampshire on Sunday.

In an interview with CBS News' Face the Nation, Bennet called Trump, "the most fiscally irresponsible president we've had in generations."

Joe Biden (D)

The former vice president responded to a number of attacks this week from rivals both inside and outside his party.

On Monday, Biden defended his son Hunter against Trump's personal lawyer Rudy Giuliani, who has made a number of efforts to investigate the work Hunter Biden did for a Ukrainian energy company while his father was focused on the country under the Obama administration. Giuliani had planned to travel to the Ukraine for more information, but cancelled his trip on Saturday.

Facing criticism from New York Rep. Alexandria Ocasio-Cortez, and fellow 2020 presidential candidate Washington Governor Jay Inslee over his record on climate change after a report in Reuters claimed he was seeking a "middle ground" solution on the issue, Biden told reporters at a campaign stop in New Hampshire, "I've never been middle of the road on the environment. Tell her to check the statements that I made, and look at my record and she'll find that nobody has been more consistent about taking on the environment and a Green Revolution then I have."

Bill de Blasio (D)

The New York City Mayor officially announced his campaign on Thursday morning and then appeared on Good Morning America, for his first presidential campaign interview.

"Donald Trump is playing a big con on America, I call him 'Con Don' every New Yorker knows we know his tricks, we know his playbook. I know how to take him on," he told ABC News Chief Anchor George Stephanopoulos.

But even in the first hours of his campaign, de Blasio faced immediate pushback. As the mayor spoke on ABC's "Good Morning America," protesters outside the studio chanted "liar" and blew whistles loud enough to be heard inside.

Cory Booker (D)

Booker continued to outline his sweeping proposal to combat gun violence this week, rolling out a new slate of ideas geared toward addressing gun suicides.

On ABC's "This Week," Booker compared the fight against gun violence to the Civil Rights Movement.

"People thought [civil rights legislation] was impossible, but they changed the terms of the debate by expanding the moral imagination of this country," Booker, D-N.J., told ABC News Chief White House Correspondent Jonathan Karl, just prior to opening a campaign office in South Carolina.

In that same interview Booker bashed a proposal from Massachusetts Sen. Elizabeth Warren to break up big tech companies as not befitting a president and sounding "more like a Donald Trump thing to say."

Steve Bullock (D)

Bullock officially launched his presidential campaign this week, becoming the only candidate in the race so far to win a statewide election running alongside then-candidate Donald Trump.

"As a Democratic governor in a state Trump won by 20 points, I don't have the luxury of only talking to people who agree with me," Bullock said in his announcement video posted Tuesday morning. "I go all across our state's 147 thousand square miles and look for common ground to get things done."

ABC News got an exclusive inside-look at Bullock's campaign launch, and followed along with the candidate to the same high school in Helena, Montana that he attended.

His daughter Caroline said of running for president, "It's a mindset that you want to go out there and change the world."

Pete Buttigieg (D)

Buttigieg continued to keep a steady pace, making headlines in California as he courted Hollywood stars to build on his impressive fundraising totals from the first quarter of the year, even as he may be seeing his initial surge of support in the polls fade.

Politico reported on Wednesday that Buttigieg hired Larry Grisolano and John Del Cecato of AKPD Message and Media, the same firm that helped propel Barack Obama to victory in the Democratic primary in 2008.

Julian Castro (D)

Castro unveiled a sweeping education plan this week that would create a national federally funded pre-kindergarten program, eliminate tuition at public universities and community colleges and alter the student-debt repayment process.

"What I see out there is that the United States right now is falling further and further behind other nations in terms of making sure that our children are well educated and have the knowledge and the skills that they need to succeed in the 21st century global economy. And I want to make sure that Washington is a strong partner with states and local school districts," Castro told Boston radio station WBUR on Monday.

John Delaney (D)

In an interview with the live streaming news network Cheddar, Delaney criticized Trump's trade policy toward China.

"In many ways, he's the mirror image of the Chinese. They don't sell a set of values, they don't sell kind of a global order if you will, they don't sell allies, they sell transnational relationships," the former Maryland congressman said.

Delaney returns to Iowa next week for a three-day campaign swing that includes an immigration roundtable, community meet and greets, a tour of flood damage and recovery, and a tour of a mental health facility, according to his campaign.

Tulsi Gabbard (D)

In an interview on ABC News' The Briefing Room Gabbard offered a sharp critique of Trump's foreign policy, specifically towards Iran.

The congresswoman from Hawaii and Iraq War veteran said the Trump administration -- specifically calling out John Bolton -- are exaggerating the threat Iran poses to the world.

"There hasn't been a comprehensive presentation of the intelligence that the administration keeps citing," Gabbard said. "What we have heard so far has been shallow and superficial at best."

Gabbard compared the dialogue coming from the administration to the lead up to the Iraq War.

"The reality of what we're seeing here is it appears John Bolton is using that same play book once again to lead our country into war with Iran."

Kirsten Gillibrand (D)

Gillibrand criticized the Democratic National Committee's 65,000 individual donor threshold for making the debate stage, telling CNN it is an "odd measurable" to gauge the strength of a candidate.

"Like, why do you make that your measurable as opposed to have you won elections before and have you ever run statewide before and how many votes have you gotten before and have you passed legislation and are you effective in your job?" Gillibrand asked.

The New York Senator also traveled to Georgia on Thursday and met with a group of women leaders to assail what Gillibrand has called "horrific" anti-abortion measure that Gov. Brian Kemp recently signed into law.

Kamala Harris (D)

In a not-so-subtle jab at Biden, Harris on Wednesday slammed recent talk that she would be a great running mate -- for the former vice president.

"Sure, if people want to speculate about running mates, I encourage that. Because I think Joe Biden would be a great running mate," Harris told reporters at a campaign stop in New Hampshire. "As vice president, he's proven he knows how to do the job, and there are certainly a lot of other candidates that would make for me a very viable and interesting vice president."

The California senator announced on Tuesday that if she becomes president, she will take executive action to ban imports of all AR-15 style assault weapons.

John Hickenlooper (D)

Hickenlooper continued to pitch himself as a proud capitalist, telling Yahoo Finance, "When I was a kid, capitalism provided security and opportunity. That challenge, of how do we make capitalism work for everyone again, is critical to the future of American democracy."

The former Colorado governor also made a point of specifically separating himself from Elizabeth Warren's rejection of Fox News, tweeting before an appearance on the network that while he agrees media is "too polarized," he does not "believe we should stop talking to people who don't agree with us."

Jay Inslee (D)

Inslee unveiled the second leg of his sweeping proposal to combat climate change: a $9 trillion investment in jobs, clean energy and modern infrastructure.

The Washington governor also signed into law legislation that makes the state the first to enter the private health insurance market with a universally available public option, according to The Associated Press.

Amy Klobuchar (D)

Klobuchar became the latest 2020 candidate to visit Puerto Rico this week, and sat for a lengthy interview with Elle Magazine, where she discussed her career in public service and decision to run for president.

When asked about a now-infamous story about her eating a salad with a comb after realizing she didn't have a fork, the Minnesota senator said there will always be crazy stories that come out when running for public office, but what she's focused on is winning over Democratic voters.

"You just have to stay grounded in the reason that you're doing it: For your neighbors and fellow Americans across the country who want to see someone in office who's going to bridge the divide and work to get things done, which is what I've done my whole life," she said.

Beto O'Rourke (D)

In the midst of middling poll numbers and a spate of stories depicting a campaign eager to reset the narrative, O'Rourke gave two highly-publicized national interviews, including an extensive sit down with ABC's "The View," where he acknowledged some early missteps in his presidential bid.

O'Rourke said his decision to appear on the cover of Vanity Fair prior to his campaign launch was a mistake.

"Yeah, I think it reinforces that perception of privilege and that headline that said I was, 'I was born to be in this' in the article I was attempting to say that I felt that my calling is a public service," he said. "No one's born to be president of the United States of America."

The former Texas Congressman will re-enter the national spotlight yet again next week with a live town hall on CNN from Des Moines, Iowa slated for Tuesday evening.

Tim Ryan (D)

Ryan, who's working to position himself as the blue-collar Democrat in 2020, weighed in on Trump's escalating trade conflict with China this week. Telling PBS that imposing tariffs "needs to be part of a larger strategy."

"I've been at the epicenter of de-industrialization" Ryan said. "What makes me different is that I have that experience, but also that I've been thinking about how to improve economic opportunity."

Bernie Sanders (D)

The progressive leader became the latest 2020 hopeful to join the chorus of candidates calling to break up big tech companies like Facebook.

"The answer is yes of course," Sanders told Politico. "We have a monopolistic -- an increasingly monopolistic -- society where you have a handful of very large corporations having much too much power over consumers."

Sander's comments follow fellow progressive Democratic candidate Elizabeth Warren leading the charge to "break up our biggest tech companies" to remedy what the Massachusetts senator views as an imbalance of power and lack of competition.

Howard Schultz (I)

After weeks of downtime it's starting to become clear why the former Starbucks CEO's 2020 flirting has subsided, at least publicly. "A strong Joe Biden nomination would narrow options for Howard Schultz," a source close to the centrist billionaire tells ABC News.

However, despite being silent on social media after an initial media blitz earlier this year, Schultz is reportedly still considering a run.

Based on conversations with the team, Schultz was always looking to play the long game, and and now his decision could come as late as next year.

Eric Swalwell (D)

While some 2020 Democrats this week came out against appearing on Fox News and disavowed giving the network a bump in ratings (see Warren below), Swalwell said that he'd love to appear on the cable news network -- they just won't have him.

"I would absolutely do a Fox town hall," Swalwell told CNN. "But they told us we can't have one which is a little bit confusing to us because they have given them to people who are polling at the same place as us."

Elizabeth Warren (D)

The "I've-got-a-plan-for-that" candidate continued to step out in front of the 2020 field this week, becoming the first Democrat running for president to denounce appearing on Fox News.

Warren said she wouldn't go on the network, slamming Fox News as a "hate-for-profit racket."

"Hate-for-profit works only if there's profit, so Fox News balances a mix of bigotry, racism, and outright lies with enough legit journalism to make the claim to advertisers that it's a reputable news outlet," Warren wrote on Twitter. "It's all about dragging in ad money -- big ad money."

Warren's fiery words follow Sanders making waves last month when be became the fist 2020 Democrat to sit for a town hall on Fox News.

The Massachusetts senator also pledged that If elected, she would select a public school teacher to head the Department of Education, taking aim at Trump's appointed secretary

"I'll just be blunt: Betsy DeVos is the worst Secretary of Education we've seen," Warren said.

Marianne Williamson (D)

The spiritual guru and best-selling author qualified for the upcoming June debates.

Williamson's campaign says she has crossed the 65,000-donor threshold, but has yet to reach 1% in three national polls, the other way a candidate can qualify.

"What I'm trying to do is tell the truth as fiercely and as accurately as I know it," Williamson told ABC News in reaction to the news.

Andrew Yang (D)

The former startup CEO joined other fellow 2020 Democrats in saying that big tech companies would be "well served" if broken up into smaller entities.

Speaking to ABC News' Senior Congressional Correspondent Mary Bruce and Political Director Rick Klein on the Powerhouse Politics podcast on Wednesday, Yang said: "I think in many cases they are too big. … We would be well served by having them break themselves up into different parts of their businesses."

But the leader of the "Yang gang" did admit that the issue surrounding massive tech companies is "more nuanced than just breaking them up."

"It doesn't actually solve many of the problems," he added.