PHILADELPHIA — Hillary Clinton’s campaign team sought to tamp down controversy Monday on the first day of the Democratic National Convention, saying Sen. Bernie Sanders, Clinton’s chief rival for the party’s presidential nomination, will help the rank-and-file “unite” behind the former secretary of state and New York senator.

Clinton campaign manager Robbie Mook sought to portray a contrast with the Republican convention last week, where Sen. Ted Cruz (R-Texas) refused to endorse party nominee Donald Trump. Sanders was set to address his supporters at a separate gathering at midday, then speak later on the convention’s opening night; his supporters, meanwhile, were planning a downtown protest march Monday.

“Senator Sanders will unite the party to ensure that she wins,” Mook said, referring to Clinton. “That is not what we saw last week with Senator Cruz.”

But while proclaiming unity, Mook and campaign spokesman Brian Fallon had to parry questions about Sunday’s abrupt resignation of DNC chairwoman Debbie Wasserman Schultz, which came after a WikiLeaks email dump that appeared to show she was tilting the primary process in favor of Clinton and at Sanders’ expense.

Mook said the resignation was Wasserman Schultz’s decision, sidestepping the enormous pressure coming from Sanders and his supporters for her resignation.

Mook also continued to maintain that security “experts” say the DNC emails were hacked by “Russian-state actors” who were “for the purposes of helping Donald Trump.”

Trump, who has often praised Russian President Vladimir Putin, has mocked the Dems’ explanation.

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Mook, meeting with the media to kick off the convention, said the next four days would focus on a “optimistic, hopeful” future that would contrast with Trump’s “doom and gloom.”

Fallon announced that following the convention Clinton and her running mate, former Virginia Gov. Tim Kaine, would hold a rally in downtown Philadelphia on Friday, then continue on a bus tour through the heart of Pennsylvania and Ohio. He said Clinton will compete with the Rust Belt and rural working class voters that Trump is targeting.

“We are leaving no voter untouched in this campaign,” Fallon said.