Sen. Charles E. Schumer and Rep. Hakeem Jeffries, the top Democrats on Capitol Hill, threw their support behind Vice President Kamala Harris’ bid for the presidency, becoming two of the highest-profile Democrats to back her.

Schumer and Jeffries announced their endorsements together in a townhouse near the Capitol on Tuesday that’s home to the Senate’s main campaign operation. Both had initially held out on endorsing Harris after President Joe Biden announced Sunday that he wouldn’t seek a second term, but said she had rallied grassroots supporters to her campaign and built up her support.

“She said she would work to earn the support of our party and boy, has she done so in quick order,” Schumer said. “The vast majority of my senators quickly and enthusiastically endorsed her. So now the process has played out from the grassroots bottom up, we are here today to throw our support behind Vice President Kamala Harris.”

Harris had no actual opposition. After Biden backed her to succeed him on Sunday, several Democrats who were considered contenders to launch their own campaigns also endorsed Harris. More than 3,000 elected Democratic delegates pledged to support her as of Tuesday morning, according to an Associated Press survey, more than enough for her to secure the nomination on the first ballot of a roll call vote. 

Schumer and Jeffries, both New Yorkers, predicted that with Harris at the top of the ticket, Democrats would win the White House, keep control of the Senate and flip the House.

“In just the last 36 hours, I have seen a surge of enthusiasm form every corner of our party uniting behind Vice President Harris, an enthusiasm felt in every corner of the country and it’s contagious among Democrats,” Schumer said.

The pair are set to meet with Harris “soon,” Schumer said.

Harris traveled to Milwaukee on Tuesday for her first campaign rally as the likely presidential nominee. Biden, who has been recovering from COVID at his beach house in Delaware, planned to return to Washington on Tuesday and is set to address the nation from the Oval Office on Wednesday night. 

Early polls have suggested that Harris is faring better than Biden was in recent weeks at the top of  the ticket. 

A Reuters/Ipsos national poll conducted Monday and Tuesday found that Harris led former President Donald Trump, the Republican nominee, 44 percent to 42 percent, within a 3 percentage point margin of error. 

The Trump campaign released a memo from pollster Tony Fabrizio saying he expected polls to show a “Harris honeymoon” in the coming weeks. Harris could see a polling bump ahead of next month’s Democratic convention, which often leads to polling bumps for candidates, but he predicted the race would eventually settle down.

“The fundamentals of the race stay the same,” he wrote. “The Democrats deposing one Nominee for another does NOT change voters’ discontent over the economy, inflation, crime, the open border, housing costs not to mention concern over two foreign wars.”

Priorities USA, a progressive organization supporting Harris, said that before Biden’s withdrawal from the race, support had been lagging in groups that were key segments of his 2020 victory, including Black and Latino voters. Harris is already making inroads with those groups, leaders of the group told reporters Tuesday.

They predicted that five states – Michigan, Wisconsin, Pennsylvania, Nevada and Arizona – would determine the election. 

“It’s going to be a close, hard fought election. That continues to be true,” said Nick Ahamed, the group’s deputy executive director for political partnerships, analytics and opinion research strategies.