Washington — Vice President Kamala Harris' presidential campaign said it brought in $200 million in the one week since President Biden exited the race and endorsed Harris, as the bulk of the Democratic Party has rallied behind her campaign and bolstered the late entry into the race. 

The campaign, which announced the total on Sunday, said 66% of the funds came from first-time donors, touting grassroots support for Harris' bid. And the campaign said the support has extended to its volunteer effort, with over 170,000 new volunteers coming onboard since last week's announcement. 

"Vice President Harris has been a candidate for less than a week, but she's already coalesced the entire Democratic Party around her campaign and the organic, grassroots enthusiasm is producing results," the campaign's communications director, Michael Tyler, wrote in a memo.

The fundraising haul comes after the campaign said it raked in more than $100 million in the day following Mr. Biden's announcement that he would suspend his campaign. In the days that followed, Harris received endorsements from large swaths of the party, including individuals who had been seen as possible White House contenders, while winning endorsements from the bulk of the party's 4,000 pledged delegates — making her the presumptive nominee. 

On Saturday, Harris attended her first major fundraiser since becoming the presumptive Democratic presidential nominee. The party will officially select its new nominee in early August in a virtual roll-call vote. 

Harris made the campaign pitch at an event in Pittsfield, Massachusetts, where she spoke to more than 800 attendees, many of whom were Democratic donors. The fundraiser raised $1.4 million, according to a Harris campaign official, outperforming an initial goal of $400,000. The event came as part of what the campaign has dubbed a "weekend of action," which comes 100 days ahead of election day.

Harris is expected to select a running mate in the coming days. Her campaign has started a "thorough" selection process, her campaign manager told CBS News on Friday. And among the names the Harris campaign has been vetting are roughly a dozen Democrats, a source familiar with the process told CBS News last week. Multiple sources confirmed that the list included Governors Andy Beshear of Kentucky, Gretchen Whitmer of Michigan, Roy Cooper of North Carolina, J.B. Pritzker of Illinois, Josh Shapiro of Pennsylvania and Tim Walz of Minnesota, as well as Sen. Mark Kelly of Arizona. 

Aaron Navarro and Nidia Cavazos contributed reporting.