Arkansas Democratic Senator Blanche Lincoln was not expected to win Tuesday night's primary runoff against Lt. Governor Bill Halter. Considered too moderate to retain her party's bid and expected to be yet another casualty of anti-incumbent rage, pundits predicted doomsday. But win she did, by a margin of only 3,000 votes. Here's what we can learn from the race and its results.

• Nationwide, the Party Base Is Motivated  The Washington Post's Ezra Klein writes, "Part of the narrative that's emerged is that these primaries show an anti-incumbent, anti-Washington, year. That's right, but it's mixed, incoherently, with pro-party -- which is to say, pro-Washington establishment -- results. The different bases are eliminating politicians who've been insufficiently dedicated to holding their party's line. The result will be much more significant than merely the election of three new senators. Rather, surviving senators will upgrade the threat an unhappy base poses to their reelection and trim their independence accordingly."

• Big Defeat For Big Labor  The Weekly Standard's Daniel Halper notes that a White House official told Politico, "Organized labor just flushed $10 million of their members' money down the toiled on a pointless exercise." Halper adds, "But it's more than just the money. It's a rejection of the ideas the unions are peddling. The unions wanted this election. Bill Halter, Lincoln's Democratic primary opponent, is for card check. Lincoln is not. Card check is the unions' signature issue."

• 'Anti-Incumbent Sentiment' Not So Universal  The New York Times' Carl Hulse writes, "On a primary election night when the heralded anti-incumbency sentiment was expected to again demonstrate its strength, Senator Blanche Lincoln proved there were clear limits to its power."

• She Promised to Change  The Economist's Democracy in America says that when "Blanche Lincoln returns to the Senate, she may not be Blanche Lincoln anymore (at least not when an election nears). The senator already claims to have learned her lesson. In her final campaign spot she acknowledged voters' anger, and her response in Washington was to favour derivatives legislation that was to the left of what many Democrats had in mind. But it may be too little, too late."

• Dems Knew Halter Had No Chance  Polling wizard Nate Silver suggests, "it's also silly to think that Halter could have won the general [election] in Arkansas. If you don't trust Rasmussen and Research 2000 polling because of their extreme house effects, the only other poll of that race was from Mason-Dixon, and it showed Halter losing to Boozman by 24 points."

• She Just Ran a Slightly Better Campaign  The Atlantic's Marc Ambinder cautions against reading too much into the race, given its incredibly tight margin. "It's a funny habit we political pundits have. If, say, 3,000 votes separate a winner from a loser, we forget that a small shift in some part of a state could have swung those votes the other way, and we tend to massively over-interpret the meaning of the tiniest of margins. ... There wasn't much ideological room between Halter and Lincoln." Ambinder instead cites campaign tactics, like bringing in Bill Clinton on Lincoln's behalf and the candidates' get-out-the-vote strategies.

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