PHILADELPHIA — Rep. Debbie Wasserman Schultz, chairwoman of the Democratic National Committee, announced her decision to resign Sunday amid controversy over leaked emails that exposed the DNC's underhanded efforts to stifle Sen. Bernie Sanders' popularity during the primary.

Her resignation will become effective at the end of the convention, where she had already been stripped of her prime-time speaking role as calls for her to step down grew louder over the weekend.

Wasserman Schultz cited her desire to focus on boosting Hillary Clinton in Florida, where she is running for re-election, in a statement announcing her decision to step down just one day before the Democratic convention begins here in Philadelphia.

"Going forward, the best way for me to accomplish those goals is to step down as party chair at the end of this convention," she said. "As party chair, this week I will open and close the convention and I will address our delegates about the stakes involved in this election not only for Democrats, but for all Americans."

Wasserman Schultz had faced pressure to leave the DNC since Friday, when a massive leak of internal documents suggested DNC officials had conspired to attack Sanders on his religion ahead of primaries in West Virginia and Kentucky. Her stewardship of the party has been under near-constant fire throughout this primary season, with supporters of Sanders smelling collusion long before WikiLeaks released stolen DNC emails.

DNC Vice Chair Donna Brazile will preside over the party until the election, a DNC spokesman said Sunday.

The DNC leak that felled Wasserman Schultz cast a cloud over the convention as Democrats gathered to nominate Clinton later this week. Sanders supporters had only recently — and begrudgingly — shifted their allegiance to Clinton when the Vermont senator threw his full weight behind her earlier this month.

The news that the DNC's pattern of favoritism toward Clinton was more than just a progressive conspiracy theory could threaten to unravel the party unity Clinton's camp has worked hard to secure in the weeks before the Democratic convention.

Wasserman Schultz repeatedly fended off criticism over her handling of the 2016 primaries. For example, she argued the DNC's decision to cap the number of debates was not a move that favored the former secretary of state, even though Clinton's detractors felt the smaller debate slate unfairly punished Sanders.

The Florida congresswoman has a history of making controversial and even false statements, a habit that made her five-year tenure contentious.

President Obama praised Wasserman Schultz Sunday, noting in a statement that he had called the embattled DNC chair earlier in the day.

"Her leadership of the DNC has meant that we had someone who brought Democrats together, not just for my re-election campaign, but for accomplishing the shared goals we have had for our country," Obama said.

Clinton announced in a statement that Wasserman Schultz would join her campaign as honorary chair of a 50-state program to help down-ballot Democrats.

The upheaval within the Democratic Party will almost certainly cast a pall over Clinton's convention, which had been billed as a more organized counter to the Republican convention in Cleveland last week.

But longtime Democratic consultant, and former Howard Dean campaign manager Joe Trippi disagreed, musing that the Wasserman Schultz scalp might placate Sanders supporters.

"All this anger from Bernie people?" Trippi said, "It actually could just blow off with what she just said."

Tim Carney contributed to this report.