The House Financial Services Committee has grown so large that a highly unusual fourth row of seats had to be installed in the committee room. Every term, scores of members, particularly freshmen, demand a seat on the panel — not because they have a burning interest in regulating banks and Wall Street, but because they know that they will be able raise much more money if one of the 61 seats has their name on it.

As Eric Lipton recently explained in The Times, Financial Services has become known as “the cash committee” because interest groups donate more money to its members than to those of any other House committee. More than $10 million has been given to its members just this year, and most of it has come from the big names the committee oversees. Contributors included employees of Goldman Sachs, Bank of America, the Credit Union National Association, the Investment Company Institute, Wells Fargo and many of the biggest accounting firms and insurance companies.

Committee members don’t seem particularly ashamed of the favors they do for those providing the cash. Andy Barr, a freshman Republican from Kentucky, promised to protect a tax break worth $500 million to credit unions. (They gave him $15,000.) And he introduced a bill that would allow banks to give mortgages to people who cannot afford them, undoing a federal rule at the request of the big banks’ lobbyists. (Banks have given him at least $47,000.)

That’s a lot of money for a little-known freshman. In fact, the $150,000 he has taken in from the financial sector in the last six months is almost as much as those interests gave Speaker John Boehner and other leaders. It’s the banks’ way of saying, welcome to the committee and our culture, we hope we can continue to do business. “We make an investment, and we are hopeful that investment produces a return,” an industry lobbyist told Mr. Lipton.