Newton Mayor Setti Warren (D) will drop out of the Massachusetts Senate race Thursday, the Boston Globe reported late today and a Democratic source confirmed to Roll Call.

Warren, not even two years into his first term as mayor, struggled to raise money since he announced his bid in May. He had only $55,000 in cash on hand at the end of June and more than $77,000 in debt, according to Federal Election Commission filings.

A former aide to Sen. John Kerry (D-Mass.) and President Bill Clinton, Warren also served in Iraq in the Navy Reserve before running a successful campaign to be mayor of his hometown.

Warren was firm when pressed earlier this month in Boston by Roll Call about his ability to compete in the race to unseat Sen. Scott Brown (R) next year.

“Scott Brown has made the wrong decisions for our state, and I believe I have the strongest chance to beat him next year,” he said, adding that he was proud of the support he had already garnered. “This is an 18-month marathon.”

But it turned out to be more of an unfinished sprint. He never gained the traction he needed, and with the recent entrance of Harvard professor Elizabeth Warren, who has strong backing from the Democratic establishment in Boston and Washington, D.C., and is expected to be a fundraising powerhouse, it became increasingly clear that there wasn’t room for two Warrens in the race.

Roll Call rates the Massachusetts Senate race a Tossup.