In last week’s lede editorial, the editors wrote:

The stinging defeats of the Bush years (and, stretching back, of the age of Reagan) have induced a nagging self-doubt among many on the center-left. They just don’t trust that a majority of people are actually with them–or they’ve stopped believing that public sympathy will mean much once the right unleashes its culture-war arsenal. But a CBS/New York Times poll showed a majority opposed to the gas tax cut, exit polls showed voters to be largely unfazed by Reverend Wright, and Obama maintained or increased his share of the working-class white vote in Indiana and North Carolina. Which means: blue-collar voters, and voters in general, are smart enough to see through the condescension of politicians selling a policy their own advisers say is bunk or peddling guilt by association.

So, too, it seems with the good voters of Mississippi’s first district, who last night elected Democrat Travis Childers with a comfortable eight point margin.

A few weeks ago, in the midst of the hotly contested race, the NRCC ran an ad attacking Childers for having received the endorsement of Barack Obama, saying “When Obama’s pastor cursed America, blaming us for 9/11, Childers said nothing.”

If there’s anywhere, an ad like this could have some serious effect, it would be in Mississippi’s heavily Republican (and white) first district. But Childers’ victory last night can instead be added to a growing cluster of datapoints that suggest we’ve reached a point of diminished returns for the Rove-style politics that have been so effective these last eight years.