Top Stories
Top Stories

Bernie's in for Hillary: Why getting his supporters will matter, too

The joint Bernie Sanders-Hillary Clinton event in New Hampshire on Tuesday was the result of weeks of back-channel wooing by the former secretary of state's campaign.

Clinton strategist Robby Mook spoke regularly with Sanders campaign chair Jeff Weaver as it became clear that Clinton would have the delegates necessary to secure the nomination later this month in Philadelphia. And as Politico Playbook reports, New York Sen. Chuck Schumer played a critical peace-brokering role as did President Barack Obama.

Sanders wanted strong progressive language in the Democratic platform on such issues as Wall Street reform, the environment and the minimum wage. He lost on including language repudiating the Trans-Pacific Partnership trade deal but overall the Vermont senator's stamp is all over the document.

Bernie Sanders supporters with signs at the Team Bernie LA Rally on June 26, 2016 in Los Angeles, California.
Rodin Eckenroth | Getty Images

The endorsement and campaign event was critical for Clinton as she seeks to bring Sanders's anti-establishment supporters into the fold as some polls show presumptive Republican nominee Donald Trump closing the gap and potentially making the presidential race a nail-biter.

The latest NBC News/Survey Monkey tracking poll has Clinton up just 3 points on Trump. The poll found that 82 percent of Americans felt it was inappropriate for Clinton to use a private server for her email while at the State Department. Somewhat amazingly, 20 percent of Clinton's own supporters said they disagreed with the Justice Department's decision not to prosecute her over the email setup.

Those figures highlight the critical importance of a full-throated Sanders endorsement and a significant campaign role for the Democratic primary runner-up. Sanders regularly ripped Clinton during the campaign as an untrustworthy creature of the establishment backed by Wall Street. The attacks won him a strong following, especially among younger voters who have not warmed to Clinton.

The presumptive Democratic nominee already has strong support from key parts of the Obama coalition including African-American and Latino voters. But she continues to struggle with younger voters whom she will need to turn out in significant numbers to win in November. A new GenForward poll found that only half of Sanders' young supporters are now willing to support Clinton.

According toThe Washington Post, Sanders won more voters under age 30 than Clinton and Trump combined during the primaries, and it wasn't even close. That fact helps explain Clinton's recently released college affordability plan. And it makes the Sanders event a critical fist step in convincing millennial voters that the former first lady understands their problems and can be trusted to address them.

Expect the Clinton campaign to turn to Sanders often during the next four months to appeal to younger voters and to give him a prominent role at the Democratic convention in Philadelphia.

Hillary Clinton, presumptive 2016 Democratic presidential nominee, speaks during a campaign event in Atlantic City, New Jersey.
John Taggart | Bloomberg | Getty Images

The endorsement and joint campaign event ends potential nightmare scenarios for Clinton, including a third-party run by Sanders that could hand the White House to Trump. It should also make it even more difficult for Trump to try to woo Sanders voters who are eager to shake up Washington with an outsider candidate.

It's not likely that young Sanders voters will ever be thrilled at the prospect of voting for Clinton. But if their hero can at least get a majority of them to hold their noses and vote for her in November it will be a big win for Clinton.

The dream scenario for the Democratic standard bearer is now beginning to take shape. She no longer faces the threat of indictment. Sanders is coming on board. Now her Brooklyn headquarters will hope for a messy nominating convention for Trump followed by a strong showing of party unity in Philadelphia. Then it's on to the debates, an arena where Clinton supporters expect her to shine.

—Ben White is Politico's chief economic correspondent and a CNBC contributor. He also authors the daily tip sheet Politico Morning Money []. Follow him on Twitter .