WASHINGTON -- Just three months after his victory over incumbent Melissa Hart, U.S. Rep. Jason Altmire is keeping a brisk fund-raising pace.

The freshman Democrat from McCandless collected more than $74,000 between the Nov. 7 election and the end of the year, according to campaign finance data released last week. In January, he held three fund-raisers. Another is planned for Wednesday at the Democratic Club here.

Thousands of dollars have come from special-interest groups that, before the election, heavily supported Ms. Hart, formerly one of the Pennsylvania congressional delegation's most powerful Republicans.

Mr. Altmire is hardly unique. Democrats gained 30 House seats in November, giving them control of the chamber for the first time in a dozen years. Now, freshmen who overcame Republican incumbents feel pressure to start preparing for tough re-election battles of their own in 2008, when the GOP will try to reverse those losses.

Rep. Patrick Murphy, a new Democratic member from the Philadelphia suburbs, raised $47,000 in the most recent reporting period. He defeated former Rep. Michael Fitzpatrick last year by about 1,500 votes, and Mr. Fitzpatrick could be a contender for the seat again.

Pennsylvania politicos also are speculating about Mr. Altmire's potential rivals.

"In the current game, you have to raise huge amounts of money," said Nick Nyhart, president of Public Campaign, which advocates for public financing of elections.

In the 2006 election cycle, Mr. Altmire, a former executive at UPMC, raised more than $1.1 million, with close to $800,000 coming from individual contributions. Ms. Hart raised nearly twice as much, and the majority of her donations came from the political action committees for groups that lobby on behalf of specific issues or industries.

Since the election, some new special-interest groups have started pouring money into Mr. Altmire's campaign coffers. Several of his donors also gave considerable sums to Ms. Hart.

Pfizer Inc., which gave $8,500 to Ms. Hart before the November election, contributed $1,000 to Mr. Altmire on Dec. 20, according to the Federal Election Commission. Norfolk Southern Corp. gave Ms. Hart $5,000 between July 2005 and September 2006. In December, the company's "good government fund" gave $1,000 to Mr. Altmire.

The American Bankers Association, which gave $12,000 to Ms. Hart before the election, donated $5,000 to Mr. Altmire's campaign committee on Nov. 27.

A spokesman for the bankers association declined to comment.

"They sort of hedge their bets. It's the norm," Mr. Nyhart said. "The rule of thumb is to give to the incumbent, not the challenger."

Now, as the incumbent, Mr. Altmire is in a position to raise larger amounts of money from groups that wanted to gain Ms. Hart's favor in the past. But Mr. Altmire said his new donors shouldn't count on any special benefits.

"I'm certainly not going to turn down help if folks want to help," Mr. Altmire said in an interview. And, "I'm certainly not going to give any favoritism to these groups."

The mixture of money and politics has long been a controversial subject. Last year saw high-profile corruption scandals entangle several prominent politicians, including former Rep. Bob Ney of Ohio and former House Majority Leader Tom DeLay, both Republicans, and Rep William Jefferson, a Louisiana Democrat. A scandal involving the lobbyist Jack Abramoff may lead to more revelations in the months ahead.

Many Democrats, including Mr. Altmire, ran on platforms decrying those scandals and promising a change.

Mr. Altmire signed onto the "Voters First Pledge" of the Public Campaign Action Fund, Common Cause, Public Citizen and other groups who argue that public financing of elections would allow politicians to spend less time raising money and more time tending to the concerns of constituents.

"I'd support and work hard to pass any bill that takes money out of politics," Mr. Altmire said.

In the meantime, he's not willing to sit back and let potential challengers amass their own campaign war chests unchallenged.