Indiana's 2nd Congressional District lives around South Bend, home of the venerable University of Notre Dame and a Democratic bastion. So is Michigan City and surrounding LaPorte County. Elkhart County is wingnut country, as are the countries to the South. The district is 85 percent white, 8 percent African American, and 5 percent Latino.
Held by Democrat Tim Roemer in the 90s, Democrats redistricted the area to maximize Dem chances of retaining the seat (note how the district grabs Kokomo -- an industrial Democratic city -- in the southeaster corner of the district). As in GA12 and other such "Democratic" districts in 2002, the national GOP wave swept in a Republican.

Chris Chocola, a carpetbagger in 2002, currently holds the seat after a narrow 50-46 victory. His margin of victory was a mere 9,000 votes out of nearly 200,000 cast. The defining issue in the race was NAFTA -- with Chocola's strong support helping him land the influential endorsement of the Indiana Farm Bureau. Bush won the district in 2000 53-44, and he campaigned heavily for Chocola in 2002, including a $650,000 fundraiser. While Bush's numbers would suggest the district is out of reach, that's not necessarily the case. Indiana voters are happy to split tickets, voting solidly Republican in presidential contests, while giving moderate-to-conservative Democrats genuine looks.
This is one of the top targeted seats this cycle. But as of Q4, Democratic candidate Joe Donnelly faced a serious fundraising deficit -- $70,000 to Chocola's $739,391 (half of it from PACs). The going rate for a House race these days is $1 million, so Donnelly has some serious ground to cover. The DCCC is likely to drop some coin into this race, helping narrow the gap, though as in most races, the Republicans will outspend our guy.
Incidentally, Indiana will be a hotbed of activity this cycle. Four of its nine districts are considered competitive -- about 10 percent of the total competitive districts in the entire House.
(I will profile the districts of all dKos Congressional campaigns advertising on the site. I think it's important for readers to understand the dynamics of the race as you make any decisions on which races to help fund.)
Update: IrishAlum weighs in, putting my little "analysis" to shame.