On Tuesday, the Senate failed to end a series of tax subsidies to the ethanol industry, but the vote was notable anyway because most Republicans voted for it. For much of the right, voting to end a tax break counts as a tax increase, making GOP support a welcome development.

The measure didn’t pass, however, because of procedural concerns from Senate Democrats. Yesterday, with those concerns addressed, a separate measure passed easily.

The Senate on Thursday approved an amendment that would end tax credits for ethanol that refiners blend into motor fuel in a vote closely watched as a sign of whether Congress can muster consensus on tax issues in the face of massive deficits.

In a 73-to-27 vote, the Senate backed an amendment by Sens. Dianne Feinstein (D-Calif.) and Tom Coburn (R-Okla.) that would abruptly eliminate the tax credits, which cost the federal government about $6 billion a year, on July 1. In addition to ending a 45- cent-a-gallon subsidy, the amendment would eliminate the 54-cent-a-gallon protective tariff that discourages imports.

The good news is, the vote wasn’t even close. It now appears that a large number of Senate Republicans are prepared to accept the idea that ending needless industry giveaways is ideologically permissible.

Indeed, right-wing uber-activist Grover Norquist, whose “pledge” is intended to forbid Republicans from even thinking about such steps, was livid. He was pushed to the point of hysterics, saying that voting to end the ethanol subsidy was evidence that Republicans had “popped” their “cherry” when it comes to taxes. Norquist called the GOP members who voted for this “sluts.”

Stay classy, Grover.

The bad news is, yesterday’s vote is likely to be symbolic. The measure is an amendment to a larger bill that’s expected to fail; it leaves many other ethanol breaks intact; and there’s little evidence House Republicans are willing to be equally constructive.

Still, baby steps in the direction of progress are better than nothing. Ideally, this will even influence the bipartisan debt-reduction talks — if Republicans are willing to accept additional sources of revenue, the likelihood of a less-insane compromise increases.

To follow up on a point from earlier in the week, though, it’s still remarkable the center of gravity has shifted so far to the right. For years, the assumption was that debt-reduction talks would always involve a combination of less spending and more revenue, with the parties arguing over the ratio. With the radicalization of the Republican Party, it’s considered a minor miracle when Dems can get the GOP to even consider both sides of the budget ledger.

What’s now seen as a major, newsworthy concession used to be a routine matter of governance.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.