Bernie Sanders to backers: 'We have got to elect Hillary Clinton'

PHILADELPHIA — A lineup of progressive speakers featuring vanquished presidential hopeful Bernie Sanders on Monday night highlight opening day of a Democratic National Convention already struggling to stay on message amid another email scandal and the ensuing resignation of the party's chairwoman.

Just days after Republican nominee Donald Trump's controversy-laden Republican convention staggered to a finale Thursday, the Democrats and presumptive nomineeHillary Clinton were stumbling out of the box themselves.

The stakes are high. CNN and CBS polls released Monday indicate that, warts and all, the GOP convention provided enough bounce for Trump to inch ahead of Clinton.

Clinton's four-day celebration took an early hit with the pre-convention release of almost 20,000 Democratic Party emails by Wikileaks, some of which showed Democratic staffers clearly favoring Clinton over Vermont Sen. Sanders in the midst of the primaries. In one email, a DNC official suggests the party could damage Sanders in the South by pressing him on his religious beliefs. In another, party chairwoman Debbie Wasserman Schultz refers to Sanders’ campaign manager as a “damn liar.”

The FBI announced Monday it was investigating a hack involving the emails.

The controversy makes Sanders' speech crucial. The Vermont senator has been gracious, saying Wasserman Schultz "deserves thanks for her years of service" but adding that "the party now needs new leadership that will open the doors of the party and welcome in working people and young people."

In a fiery warm-up speech Monday afternoon before hundreds of his delegates, Sanders made it clear he won't be leading a rebellion against Clinton.

"We have got to defeat Donald Trump,  Sanders said to cheers before drawing jeers by adding "And we have got to elect Hillary Clinton and Tim Kaine,"

But he won the crowd back over by continuing: "Trump is a bully and a demagogue. Trump has made bigotry and hatred the cornerstone of his campaign."

The email controversy led Wasserman Schultz to announce she would step down at the convention's conclusion. It also led to an embarrassing breakfast with the Florida delegation Monday, when Sanders supporters booed her off the stage. The Florida congresswoman entered the room to a standing ovation and cheers from her supporters, but quickly faced a torrent of jeers.

“I can see there’s a little bit of interest in my being here, and I can appreciate that interest,” Wasserman Schultz told the crowd.

Sanders issued a statement Sunday saying Wasserman Schultz "deserves thanks for her years of service" but adding that "the party now needs new leadership that will open the doors of the party and welcome in working people and young people."

Getting ready for my big #demconvention speech tonight! #demsinphilly pic.twitter.com/X4WJtHMliY

— Elizabeth Warren (@elizabethforma) July 25, 2016

Email has not been kind to Clinton, who survived an exhaustive investigation of her use of private email servers while secretary of State. Republicans howled foul, but the FBI declined to recommend criminal charges.

Clinton, who in a 60 Minutes interview aired Sunday called the GOP convention "dark and divisive," now must work to keep Democrats in line. Rumblings of dissent were already present, with The New York Times reporting that the Bernie Delegate Network here was "contemplating" a challenge to Clinton's vice presidential nominee, Virginia Sen. Tim Kaine.

More than 1,000 Sanders supporters marched through the city's streets Sunday, before the sanctioned activities even got rolling. Thousands more are expected at protests and marches through the week.

The Clinton camp is hoping that fiery, progressive speeches Monday night from Massachusetts Sen. Elizabeth Warren, New Jersey Sen. Cory Booker, Sanders and first lady Michelle Obama will turn the news cycle. Then the convention could become the Clinton promotional blitz her campaign — and Wasserman Schultz —worked so hard to build.

Contributing: Nicole Gaudiano