Republican presidential candidate Sen. Rand Paul, R-Ky., speaks at a presidential forum sponsored by Heritage Action at the Bon Secours Wellness Arena, Friday, Sept. 18, 2015, in Greenville, S.C. (AP Photo/Richard Shiro)

GOP presidential candidate Rand Paul -- once seen as a potential top tier candidate for his party's nomination -- raised just $2.5 million last fundraising quarter, according to a campaign filing released Thursday by Federal Election Commission.

The Kentucky senator has seen his standing in national polls sharply decline since he first announced his candidacy in April. As the second GOP candidate to formally enter the field, Paul received outsize media attention and seemed poised to ride the anti-Washington wave animating GOP voters across the country.

But he has since seen his stock among grass-roots supporters sharply decline as candidates like business mogul Donald Trump and retired neurosurgeon Ben Carson have peeled away at voting blocs Paul sought to court. Thursday's financial disclosure shows that the Paul campaign spent more last quarter than it raised, with its total disbursements totaling $4.5 million.

The campaign reported holding just $2.1 million cash on hand as of Sept. 30. For context, his campaign raised $7 million between April and June alone, with 96 percent of his contributions coming from people who gave $100 or less.

The Post's Dave Weigel reported on the campaign's woes last month:

Sen. Ted Cruz (R-Tex.) has announced endorsements from a few county leaders and legislators who endorsed Paul's father in his last presidential bid, trying to feed the idea that "liberty movement" conservatives should make a switch. And [Donald Trump] even sent out a mocking Tuesday tweet predicting that the senator would soon leave the race. ...

The slow fundraising for Paul and some supportive facts has been a source of drama and confusion for libertarians. A stark contrast to the "moneybombs" that fueled former Texas Rep. Ron Paul's campaign, the slow Paul fundraising is attributed partly to Paul's own lack of interest in donor management, and in libertarians worrying that the more pragmatic senator won't make an impact in the race.

Paul currently ranks ninth in the field according to a national polling average by Real Clear Politics, behind Ohio Gov. John Kasich and former Arkansas governor Mike Huckabee.