If Trump 'stepped forward' on gun control, it may move Republicans: Cory Booker

"It can't be a me, it has to be a we," Booker said of tackling gun violence.

"I think it's a matter of leadership, presidential leadership," the New Jersey senator and Democratic presidential candidate said in an interview on ABC's "This Week" Sunday. "I hear a lot of the pundits say that if Donald Trump actually took responsibility for this moment, and stepped forward and said this is something we should do, that it would move Mitch McConnell and a lot of other folks. We need a president that's willing to drive forward on this issue and hold people accountable."

Booker told ABC News Chief Anchor George Stephanopoulos that gun control can be an issue used to hold politicians, "who have sworn an oath ... to keep people safe," accountable.

"If they fail to be accountable, we can be able to win seats, flip, in the same way the (National Rifle Association) in the past has been able to make such a big difference in elections, so much so that many Republicans are afraid of them," the senator said. "We could flip that around, and make them afraid of the overwhelming majorities of Americans that will hold them accountable. That's the kind of tough leadership we need right now."

Several Democratic presidential candidates, including Booker, have called on Senate Majority Leader Mitch McConnell, R-Ky., to reconvene the Senate, which is currently out of session for August recess, to take up gun control legislation after two mass shootings last weekend left more than 30 people dead and dozens more injured. McConnell said he wouldn't call the Senate back during recess.

McConnell said during a radio interview on Friday, "two items that will, for sure, be front and center" for the Senate when it reconvenes in September are a background checks bill and a "red flag" warnings bill. He said that Sens. Lindsey Graham, R-S.C., and Richard Blumenthal, D-Conn., are currently working on a "red flag" bill. These type of laws allow family members or law enforcement to petition for a court order to temporarily confiscate firearms from someone if they're found to present a danger to themselves or others. McConnell also said that the bill aiming to strengthen background checks for gun purchases drafted by Sens. Pat Toomey, R-Pa., and Joe Manchin, D-W.V., will also be at the top of the Senate's priority list for September.

Trump said Friday he has "a great relationship with the NRA," but also said, "we need intelligent background checks."

"This isn't a question of NRA, Republican or Democrat," the president told reporters on the South Lawn. "I will tell you, I spoke to Mitch McConnell yesterday. He's totally on board. He said, 'I've been waiting for your call.' He is totally on board."

On Sunday, Stephanopoulos also asked Booker about a speech he gave Wednesday at Mother Emanuel AME Church in Charleston, South Carolina, addressing gun violence and the rise of white nationalism in America. Just over four years ago, a white mass shooter -- who has since been sentenced to death -- killed nine worshipers in the church, which has one of the largest and oldest African American congregations in the South.

Though he didn't mention him by name, Booker alluded to the president throughout his speech.

"The act of anti-Latino, anti-immigrant hatred we witnessed this past weekend did not start with the hand that pulled the trigger," Booker said in his speech. "It was sowed by those who spoke the same words the El Paso murderer did: warning of an 'invasion' ... It was sowed from the highest office in our land where we see in tweets and rhetoric hateful words that ultimately endanger the lives of people in our country. People of color, immigrants, of us all."

"How do you call out President Trump on the issue of white supremacy and racism without alienating his supporters?" Stephanopoulos asked.

"This impotent simplicity of who is and who isn't a racist is really not the question. ... It's not enough to say 'I'm not a racist' in America. If racism exists, you need to be anti-racist," Booker said on "This Week." "If we have a nation where someone doesn't feel comfortable, where someone is -- could be the victim of a violent attack ... all Americans should say, this is not who we are and we have something to do about it."

But Booker doubled down on his criticism of the president, saying the government, including the Department of Homeland Security and FBI, needs more resources to combat the rise of white supremacy in America, and that Trump is contributing to the problem.

"And the problem we have is in the White House (there) is not somebody who's stepping up and saying, 'We're going to deal with this, with the resources, energy,'" he said. "We have somebody who's actually adding to it, who's contributing to this kind of divisiveness and these kind of dark forces in our nation through his own rhetoric, through the way he talks about Americans.

"We have so much work to do ... in this nation on these issues, and we have a president who is failing us through everything he's doing, and worse than that, he's contributing to the problem."