U.S. Sen. Elizabeth Warren's political action committee raised more than $620,000 during the past three months, significantly boosting her efforts to help Democrats retain control of the U.S. Senate.
The amount collected in the second quarter of 2014 far outstrips the $150,000 the Massachusetts Democrat collected during the first three months of the year.
Warren ended June with more than $826,000 left in her PAC for a Level Playing Field, according to records filed with the Federal Election Commission.
The leadership PAC has raised hundreds of thousands of dollars that Warren has used to support Democratic Senate candidates and party committees including the Democratic Senatorial Campaign Committee.
Warren has also used the PAC to cover her expenses as she travels around the country to campaign on behalf of Democratic candidates in key Senate races. Since March, she has stumped for candidates in Ohio, Minnesota, Oregon, Washington and Kentucky
On Monday, she campaigned with West Virginia Democratic Senate hopeful Natalie Tennant, who is vying along with U.S. Rep. Shelley Moore Capito for the seat held by retiring Democratic Sen. Jay Rockefeller.
Warren is planning to attend a fundraiser with Michigan Democratic Senate hopeful Gary Peters, who is facing off against Republican Terri Lynn Land later this week. The two are competing to replace Democratic Sen. Carl Levin, who also is retiring.
Warren has benefited not only from individual contributors, but also from other political action committees, many of which are tied to labor unions.
PACs representing public employees, carpenters, machinists, laborers, teachers, communication workers and letter carriers each chipped in $5,000 to Warren's committee during the past three months.
Other expenses listed on the report include fundraising consulting services, accounting services and contributions to other political committees including a $5,000 contribution to fellow Massachusetts Democratic U.S. Sen. Edward Markey, who is facing a re-election campaign this year.