PHILADELPHIA, United States (AP) — Seeking to avoid a televised display of disunity, Bernie Sanders yesterday urged supporters to line up behind Democrat Hillary Clinton and claimed victory in deposing and sidelining a top party official.

Some of his supporters jeered in disapproval, indicating turmoil at this week’s Democratic National Convention won’t end with the departure of the party chairman, Rep Debbie Wasserman Schultz of Florida.

Speaking to his convention delegates, just hours before the Democrats opened a convention to nominate his primary rival, the Vermont senator tried to settle roiling tensions between his supporters and the party rank-and-file lining up behind Clinton.

A fresh e-mail controversy, appearing to show bias by party officials against Sanders, has made that task harder just as the national spotlight turns to the Democrats’ rally behind Clinton.

“Brothers and sisters, this is the real world that we live in,” Sanders told his audience, raising his hand in an effort to quiet them. Republican nominee Donald Trump is “a bully and demagogue”, he said, who must not win the White House.

The remarks were met with boos and grumbling from supporters clearly not ready to give up the fight for what he calls his “political revolution”. Sanders tried to persuade them they had already won by helping to create what he called the “most progressive Democratic platform in the history of the party”. And he, too, celebrated the ouster of Wasserman Schultz after the e-mail hack.

“Her resignation opens up the possibility of new leaders at the top of the Democratic Party that will stand with working people,” he said.

As Sanders spoke, Wasserman Schultz announced she would not gavel in the convention, recognition that her presence onstage would only showcase Democrats’ deep divisions. The Florida congresswoman was greeted with boos by delegates who would certainly have repeated the spectacle.

Clinton campaigned in Charlotte, North Carolina, yesterday, serving up a harsh critique of Trump’s foreign policy and what she said was his “trash talk about America”.

“I don’t see how you run for president of the United States if you spend all your time trash-talking the United States,” she said. “We’re going to have a convention this week that highlights success stories.”

Speaking to a convention of the Veterans of Foreign Wars, Clinton slammed many of his positions, vowing to stand by American allies, fight dictators and listen to the advice of military officials.

“You will never hear me say I only listen to myself on national security,” she said.

Clinton is within days of her long-held ambition to become the party’s official presidential nominee. She will formally accept the nomination on Thursday. President Barack Obama will speak on Wednesday night. Other high-profile speakers include former President Bill Clinton and Vice-President Joe Biden.