Donations From Colleagues Identify Vulnerable House Incumbents The Federal Election Commission continues to process campaign finance reports covering activity through March, but one pattern is already clear: which House members are most vulnerable in the eyes of their colleagues. There are a number of ways to identify such lawmakers, but one of the best is to look at who has received the most money from their colleagues in the run-up to the March 31 closing date. By that standard, Timothy H. Bishop and Sean Patrick Maloney, Democrats of New York; Ron Barber, Democrat of Arizona; and Rodney Davis, Republican of Illinois, lead the pack, which is dominated by freshman Democrats. Here is a list of the top recipients of contributions from House colleagues" campaign committees and leadership PACs, based on filings with the election commission through April 17: Mr. Bishop occupies a Long Island seat that should again be competitive next year; he beat Randy Altschuler, a Republican, in a fairly close race last November. Mr. Barber, who replaced former Representative Gabrielle Giffords, represents a Tucson-area district and barely survived a tough challenge from the Republican Martha McSally. A rematch is possible in that race, although Ms. McSally raised only a token amount in the first quarter. Mr. Maloney defeated the Republican Nan Hayworth last year and has already attracted the attention of the Congressional Leadership Fund, a super PAC with ties to the House Republican Leadership, which aired its first television advertisement of this cycle against him. Mr. Davis won his race with less than 47 percent of the vote, and Democrats are actively searching for a candidate to challenge the freshman Republican. The list does not necessarily correspond with the top House fund-raisers during the first three months of 2013, but it is a good indication of where members of the House leadership in both parties are focusing their efforts to boost fund-raising totals.