The most memorable moment in Thursday's Virginia U.S. Senate debate between Republican George Allen and Democrat Tim Kaine came early on. NBC's David Gregory asked Democratic nominee and former Gov. Tim Kaine: "Do you believe that everyone in Virginia should pay something in federal income tax?"

"I would be open to a proposal that would have some minimum tax level for everyone," Kaine responded.

This answer floored the commentariat on both sides. Kaine, a Democrat, seemed to be embracing Republican Mitt Romney's wrong-headed comments about the 47 percent of American households that pay no federal income tax. Then, later in the day, his campaign removed all doubt by patting their candidate on the back for it: "[W]hen Tim was asked if he'd be open to other proposals, he said he'd be open to talking. Isn't that what we need more of in Washington?"

In contrast to Romney, who merely complained that the 47 percent would never vote for him, Kaine was calling for -- or at least expressing "openness" to -- the much more radical notion that the 47 percent should be forced to pay more in taxes. That is, we should raise taxes on lower-income individuals and families. The only prominent Republican to call for such a thing is Rep. Michele Bachmann, R-Minn., who was upbraided by conservatives for it.

For at least a decade, Republicans have been preaching the opposite. When George W. Bush pushed for his tax cuts in 2001, he made it a big selling point that they would push millions of middle-income families off the tax rolls altogether -- and they did.

Kaine's lurch was especially bizarre because Romney's original comments about "the 47 percent" were so wrong to begin with. Among the 47 percent who don't pay federal income taxes, many will vote for Romney this year -- young conservatives, senior citizens and enlisted members of the Armed Forces. And because the payroll tax hits nearly all workers, only about 18 percent of American households pay no federal taxes on their incomes.

We did not expect to see Kaine embrace the Bachmann tax proposal to make the poor pay more. Perhaps the hundreds of coal miners in the western part of Virginia -- newly unemployed thanks to Obama's EPA and the energy policies that Kaine supports -- should ask him how much more he is "open" to making them pay.