Sean Bielat is giving Barney Frank the toughest run he’s had in decades. That’s due, in part, to the savage beatings Frank is taking over his financial ties to the financial services community he regulates. But Bielat’s campaign is being propelled forward by that same community.

Frank has recently been hit for jetting around the Caribbean with a hedge fund manager who bet against AIG, and for taking campaign donations from banks that had the courtesy to pay back the TARP money that the Treasury and the Fed made them take in the first place.

The impression that’s being encouraged by Bielat’s camp is that campaign donations from folks who work in finance are dirty, and Frank is filthy for taking it. (A video Bielat’s campaign released yesterday features Frank strutting past a Capitol building adorned with the sign, “For sale cheap! By Barney.”)

Bielat’s increasing fundraising prowess – he raised $654,000 in the first two weeks of October, easily besting Frank’s $268,000 – means we’re bound to hear lots more noise from the Brookline Marine in the next week and a half.

That’s thanks in large part to donors who work in financial services. Bielat’s campaign has raised nearly $164,000 from donors who work in finance; of that figure, $109,000 has come from outside Massachusetts.

The vast majority of that cash, some 80 percent of it, has come in since September 1.

And of the $130,000 in financial services-related donations Bielat has pocketed since September 1, more than $93,000 of it has come from out of state.

Financial services donors account for one-quarter of all itemized donations the Bielat campaign has recorded to date. (Federal campaign finance regulations don’t require a full accounting of donations less than $200.)

Some of the usual suspects (Goldman Sachs, JP Morgan, Bank of America, MFS, and Wellington Management) are represented among Bielat’s donors, but giant Wall Street firms aren’t exactly overwhelming Bielat with their generosity.

Instead, Bielat’s haul is being driven in large part by hedge funds, private equity firms, and other investment companies targeted in the financial reform package Frank co-authored this session.

Private investors from New York, New Jersey and Texas have been among the most prolific recent converts to Bielat’s cause. Ninety percent of Bielat’s financial services-related donations from New York have come in since September 1. That percentage stands at 96 percent for Bielat’s New Jersey financial services donations (a total of $16,350, as of October 13). All of the $18,150 from Texas has arrived since September 1.