The GOP’s year from hell took another turn for the worse Saturday when Republicans surrendered yet another solidly conservative House seat to resurgent Democrats.

The victory in Louisiana’s 6th congressional district came after Republicans and allies like Freedom’s Watch and the Club for Growth spent millions of dollars trying to convince voters that Democratic congressman-elect Don Cazayoux (pronounced “cashew”) was a “tax-and-spend wolf in sheep’s clothing,” that “just like Hillary,” he was a “fan of revisionist history,” and weak on national security.

As the coup de grâce, desperate Republicans, seeing their candidate Woody Jenkins lagging in fundraising and polling, decided to turn this election into a referendum on Sen. Barack Obama (D-Ill.). And they lost.

Nationalizing the race made some sense. Obama was in the midst of another Jeremiah Wright firestorm and still trying to recover from remarks suggesting that rural Americans voted Republican because they were “bitter” at the government’s inability to improve their economic lives.

Smelling blood (or simply desperate), the NRCC pounced. In one ad, they featured Cazayoux at Obama’s side, attacking his “big-government scheme” of delivering healthcare to uninsured Americans. In another, they added House Speaker Nancy Pelosi (D-Calif.) and accused Cazayoux of aiding and abetting a “radical liberal agenda.”

National political reporters, on the lookout for top-of-the-ticket narratives, took particular note of the tactic. If the ads worked and Jenkins won, it could offer proof that Obama’s promise to run strong nationally was empty rhetoric.

But the usual trite accusations have lost their power. Immigration has flopped as an issue. The repetitive “Democrats will raise your taxes” mantra is worn so thin it barely registers. Anti-gay referendums have been played out. National security concerns no longer scare people into submission. No one cares that Pelosi is from San Francisco.

So Republicans prayed that Obama’s scary black minister and some out-of-context “bitter” comments would provide just the right amount of scaremongering that makes the GOP’s electoral machine tick.

Early Saturday night, things looked good for Jenkins. The parishes outside of East Baton Rouge came in strongly for the Republican, with Republican turnout increasing from its anemic primary election levels.

But when Baton Rouge’s urban districts started to come in, things turned around in a hurry. Comprising 45 percent of the city’s population, the African-American community turned out in droves and flipped the results. By the time the dust had settled, Cazayoux had won, 49-46.

“This should come as a warning shot to Democrats,” the National Republican Campaign Committee hilariously claimed in a press release. “The elitist behavior of the Democratic front-runner and the liberal and extremist positions that he and his fellow Democrats in Congress have staked their claim to, do not appear to be as salient as they once hoped.”

This was a district that Bush had won 59-40. Only 16 Democrats out of 235 represent districts more conservative than this one. Trying to turn this into a moral victory was pathetic.

Next Tuesday, Republicans get a second crack at demonizing Obama, as he’s featured heavily in GOP attack ads in the Mississippi 1st congressional district special election, a district even more Republican than Louisiana’s 6th (Bush won it 62-37 in 2004).

If Republicans can manage to hold onto that district, maybe then they could fool themselves into thinking that Obama will actually be a problem down-ballot this November. The reality will be much different.

Moulitsas is founder and publisher of Daily Kos .