Bernie Sanders supporters are already disrupting the DNC

PHILADELPHIA—It didn’t take long for Bernie Sanders supporters to make their presence known—loudly—at the Democratic National Convention.

Sanders supporters chanted “Bernie! Bernie!” during the opening prayer on Monday, and they booed repeatedly during introductory remarks by Marcia Fudge, the convention chair.

She pleaded with them to show respect: “We are all Democrats, and we need to act like it.”

The protests were early signs that the convention would not be a smooth four-day coronation of Hillary Clinton as the Democratic nominee for president.

In the convention’s first moments, some Sanders delegates also appeared to have sneaked in signs showing their opposition to the Trans-Pacific Partnership trade deal, a signature Sanders issue.

Sanders supporters were infuriated by leaked emails that showed Democratic National Committee officials deriding his campaign and trying to undermine it.

The Vermont senator himself speaks in prime time on Monday night. At an appearance earlier in the day, he asked his followers to support Clinton and her running mate, Sen. Tim Kaine of Virginia.