When Sen. Kent Conrad, D-N.D., announced his retirement, the seat was considered a likely pickup for Republicans in an increasingly red state. But former Attorney General Heidi Heitkamp ran a very strong campaign against GOP Rep. Rick Berg. The Democrat emphasized her differences with the unpopular Obama administration, particularly on energy issues important to the state. Outside groups on both sides poured money into the state's inexpensive airwaves, and Heitkamp's television spots -- like this one emphasizing her independence -- stood out. Most polls showed a close race, but Heitkamp was still expected to lose (even Nate Silver didn't see this one coming!) -- and ultimately she eked out a razor-thin victory despite Mitt Romney's easy win in the state.
When Tommy Thompson emerged from the Wisconsin Senate GOP primary in August, national Republicans rejoiced, believing the four-term governor with a history of appealing to Democrats and independents gave them a prime opportunity to flip a Democratic-held seat. But they didn't count on Democratic Rep. Tammy Baldwin's campaign significantly changing the public's view of the longtime GOP icon. Realizing it made little sense to attack Thompson's gubernatorial record, which many Wisconsinites of both parties still remember fondly, Baldwin instead blasted Thompson with negative television ads about his post-gubernatorial career -- highlighting his work in George W. Bush's cabinet and at a Washington, D.C. lobbying firm. Baldwin's attacks caused Thompson's negatives to skyrocket. The former governor failed to attract a significant number of Democratic crossover voters, and Baldwin won by a comfortable 5-point margin.
Moving over to House races: Rep. John Barrow, D-Ga., got a helping hand from an underwhelming Republican nominee in his ride to reelection. But Barrow still needed to campaign hard to overcome a brutal Republican-led redrawing of his 12th Congressional District's lines, and that effort included one of the best TV ad campaigns we saw at any level in 2012. Members of Congress on both sides have had trouble separating themselves from their parties recently, and many candidates touting independent credentials still fell. Barrow managed to walk a tightrope between both parties, highlighting votes and issues where he split with both of them (like the Wall Street bailouts) to capitalize on voters' distrust of Washington. And in one TV ad on guns, Barrow hit on what you could call the holy grail for Southern Democrats: simultaneously appealing to his liberal African-American base and to conservative white swing voters all in the same 30 seconds.
Thanks to reapportionment, a number of House members ended up running primaries against fellow congressmen in 2012. One such race pitted Democratic Reps. Jason Altmire and Mark Critz against each other in Western Pennsylvania's 12th Congressional District. Most of the new district's residents had been in Altmire's old district, giving him a distinct advantage. But the Critz campaign and its union allies deployed an exceptional field program that swung things back toward Critz. His base counties only had 24 percent of the registered Democrats in the district, but they supplied over 31 percent of the voters in the April primary -- and almost all of them voted for Critz. That effort gave Critz just the boost he need to achieve a narrow, 51 percent primary win against difficult odds.
Critz ran another strong campaign in the general election, but it wasn't enough to overcome Republican challenger Keith Rothfus, who belongs on this list because Republicans had all but pulled their hair out trying (and failing) to beat Critz during the 2010 wave. Rothfus's "regular guy" ad campaign helped inoculate him against Democratic attacks and prevented too much split-ticket voting in a solid Mitt Romney region. It's a testament to Critz's strength as a campaigner that Republicans were very nervous about their chances in his district on Election Day; it's a testament to the Rothfus campaign that he managed to win.