Senate Republicans appear to be rallying around Sen. Jim Bunning (R-Ky.) and his one-man crusade to stop a one-month extension to federal benefits for the poor and unemployed.

Bunning’s filibuster, which he launched Wednesday and has maintained ever since, means that unemployment insurance, COBRA health insurance and other benefits will expire at midnight on Sunday.

Bunning, an acerbic Senator who is retiring at the end of this year, is demanding the benefits’ extensions be paid for and has rejected offers to hold votes on his proposals.

Although Bunning began his standoff with Democrats on his own Thursday night, Republicans have slowly started coming to his defense. Sen. Bob Corker (R-Tenn.) went to the floor Thursday evening and argued that Democrats had ambushed the 78-year-old Senator and that it was unfair to force him to actually conduct the late-night filibuster.

“If the attempt tonight is going to be to keep a man 20 years my senior here without the knowledge that this was going to happen … this, in my opinion, is beneath the Senate,” Corker said.

On Friday, National Republican Senatorial Committee Chairman John Cornyn (Texas) — whom Bunning publicly attacked last year when there were doubts about whether Bunning would run for another term — gave a full-throated endorsement of his Republican colleague’s opposition to extending the programs without paying for them.

“All the Senator from Kentucky has asked is that we do what every American family has to do and what every small business has to do and that is be honest in our indicating of the public’s money and to continue a sham, which is to pretend like we’re being fiscally responsible when, in fact, we’re not,” Cornyn said, adding that Bunning’s demand “does not seem like an unreasonable request at all.”

Democrats, however, were not so forgiving. Senate Majority Leader Harry Reid (D-Nev.) charged that Bunning’s filibuster is “irresponsible and, basically … it’s immoral.”

Brad Woodhouse, a spokesman for the Democratic National Committee, charged the entire GOP is at fault for the blockade.

“Last night we discovered just how far Republicans will go to stop the work of the American people for pure politics — even at the expense of our citizens’ health and economic security. Republican obstructionists are now training their sights on jobless Americans. … Senate Republicans — led by Jim Bunning — are playing politics with their access to federal Cobra benefits, unemployment insurance and other critical assistance,” Woodhouse said in a statement.

Senate Minority Leader Mitch McConnell (R-Ky.) — who many believe helped force Bunning from a prospective 2010 re-election bid — has not given the filibuster his blessing.