The Note: Sanders rises as Democrats fret more than act

Somehow Sanders is surging without taking harsh attacks from his rivals.

The TAKE with Rick Klein

They all see it coming. After all, it has happened before.

Yet somehow Sen. Bernie Sanders is surging in the run-up to Iowa without taking harsh attacks from his rivals.

As polls show him gaining steam in early states, all of Sanders' rivals have found ways to contrast themselves with him. Sen. Elizabeth Warren, Sen. Amy Klobuchar, former Mayor Pete Buttigieg and former Vice President Joe Biden all see Sanders as a major potential problem.

But the attacks have been subtle, and often without his name attached, in a campaign that still hasn't featured a Democrat-on-Democrat paid negative ad. The big messaging and bigger money one might expect to try to halt the self-described Democratic socialist has not materialized.

Meanwhile, Sanders has climbed to what's now a three-in-10 chance of winning a majority of convention delegates, according to FiveThirtyEight's primary forecast. That's just behind Biden, whose chances FiveThirtyEight has holding roughly steady, at two in five.

As for the lack of criticism, blame impeachment for dominating the news cycle. Blame the experience of other Democrats who have gone on the attack this campaign, only to appear to suffer because of it.

Blame the reliance on Sanders' relative lack of appeal among black voters in the South. Or blame the intensity of Sanders' backers, who are widely seen as too devoted to be persuaded -- and more likely than not to be fired up by any attacks.

But that, of course, is partly the point: The Sanders army is already a juggernaut and early wins could make him almost unstoppable. There could come a point where stopping him would require what many Sanders backers -- incorrectly -- think happened last time, with the party establishment stripping him of the nomination at the convention.

The RUNDOWN with MaryAlice Parks

The ground has shifted under the U.S. Senate. It seems more Republicans are inching towards calling witnesses in the Senate impeachment trial of President Donald Trump.

Sen. Mitt Romney said Monday morning that he thinks it's "important" to be able to hear from the president's former national security adviser John Bolton and added that he thought it was "increasingly likely" other Republicans will join him in requesting the potential witness.

The statement to reporters came after news in The New York Times over the weekend that Bolton plans to disclose his experience of the Ukraine affair in his new book and specifically call out the president for asking to freeze funds to Ukraine.

The Republican National Committee sent an email to followers accusing Bolton of trying to "boost book sales."

Still, Sen. Lindsey Graham conceded that Bolton's testimony may be needed "for fairness," but was quick to add that the move could open the door for witnesses the president has requested too, such as members of the Biden family.

The TIP with John Verhovek and Molly Nagle

He may be a key piece of the case presented by the president's legal team in the impeachment trial, and while Republican Sen. Joni Ernst of Iowa is openly speculating about the trial's impact on his candidacy, Biden is holding steadfast that he has "nothing to defend," and instead is using the attacks against him as part of his closing argument to Democratic primary voters.

"I've taken brick bats to my head … and I'm still standing and we're still moving forward," Biden told a crowd in Marion, Iowa, on Monday, while Ernst hours later wondered aloud, "The Democratic voters -- will they be supporting VP Biden at this point?"

While Biden has sometimes gotten worked up over questions of impeachment on the campaign trail -- particularly relating to his son Hunter -- he's leaning into a proactive approach in the final days leading up to next week's caucuses to prove to voters that he is the best bet to beat Trump in November.

"The reason he's on trial is because he does not want to run against me," Biden said in Cedar Falls.

THE PLAYLIST

ABC News' "Start Here" Podcast. Tuesday morning's episode features ABC News' Senior Congressional Correspondent Mary Bruce on the new calls for former national security adviser John Bolton to testify in the Senate impeachment trial. Then, ABC News Senior Transportation Correspondent David Kerley breaks down the latest in the investigation into the helicopter crash that killed NBA legend Kobe Bryant and his daughter. http://apple.co/2HPocUL

ABC News' "The Investigation" podcast. As the Senate impeachment trial enters its second week, Congressman Mark Meadows, joins "The Investigation." Meadows, who is a member of President Donald Trump's impeachment team, weighs in on the aftershocks following the New York Times report on former national security adviser John Bolton's manuscript and says that calling Hunter Biden to testify "would be a good move." Meadows also addresses his upcoming departure from Congress and possible next steps for him. "The Investigation" co-hosts John Santucci and Katherine Faulders separately discuss exclusive ABC News reporting on a recording from a small 2018 dinner with Trump that was released by former Rudy Giuliani associate Lev Parnas. https://apple.co/2mKrhcF

FiveThirtyEight Politics Podcast. In this installment of the FiveThirtyEight Politics podcast, the crew assesses Sen. Bernie Sanders's improvement in state and national polls just one week before the Iowa caucuses. They also debate whether reporting on former National Security Advisor John Bolton's new book will pressure Republican senators to call witnesses in President Trump's impeachment https://apple.co/23r5y7w

WHAT YOU NEED TO KNOW TODAY

  • President Donald Trump meets with the Israeli prime minister at 11:50 a.m. and holds a joint press conference and then holds a campaign rally in Wildwood, New Jersey, at 7 p.m.
  • Vice President Mike Pence delivers remarks at the Wisconsin School Choice Student Showcase at 12:15 p.m. (CST) in Madison, Wisconsin.
  • Former South Bend, Indiana, Mayor Pete Buttigieg holds a town hall in Ottumwa, Iowa, at 10 a.m. (CST), a town hall in Osceola, Iowa, at 12:30 p.m. and a town hall in in Indianola, Iowa, at 2:45 p.m.
  • Tom Steyer continues his bus tour of Iowa with a town hall in Ankeny at 10 a.m. (CST), a house party with Planned Parenthood at noon and a block party in Des Moines at 6 p.m.
  • Andrew Yang holds a town hall in Perry, Iowa, at 10:30 a.m. (CST) and a town hall in Nevada, Iowa, at 12:30 p.m.
  • Former Vice President Joe Biden holds a community event at 11 a.m. (CST) in Muscatine, Iowa, has a campaign stop in Davenport, Iowa, at 2 p.m. and a community even in Davenport, Iowa, at 5:15 p.m.
  • The Senate impeachment trial resumes at 1 p.m.
  • Rep. Tulsi Gabbard, D-Hawaii, will hold a snowboarding event at the Cranmore Mountain resort in North Conway, New Hampshire, at 1 p.m. and then hold a town hall in North Conway, New Hampshire, at 6 p.m.
  • Download the ABC News app and select "The Note" as an item of interest to receive the day's sharpest political analysis.

    The Note is a daily ABC News feature that highlights the day's top stories in politics. Please check back tomorrow for the latest.