For days now, Republican Sens. Rand Paul (Ky.), Mike Lee (Utah), Ted Cruz (Tex.) and Marco Rubio (Fla.) have been trying to convince us that the threat to shut down the government unless Obamacare is “defunded” (which isn’t even possible since the bulk of the monies are not tied to the annual discretionary budget) is serious. But of course it isn’t — not as long as President Obama is in the White House, Democrats have the Senate majority and/or sanity prevails in the House.

Sen. Ted Cruz (R-Tex.) (Michael Reynolds/European Pressphoto Agency) Sen. Ted Cruz (R-Tex.) (Michael Reynolds/European Pressphoto Agency)

Now the shutdown caucus confesses they don’t even have GOP support. Lee sends out a fundraising e-mail wailing that he “can’t defund Obamacare without you.” (So send money!)

Cruz concedes, “Right now, we don’t have the votes. We don’t have the votes in the House. We don’t have the votes in the Senate,” Cruz said at the gathering of Young Americans for Liberty. “I’m going to be perfectly candid, we can’t win this fight. Mike Lee can’t win this fight, I can’t win this fight, Rand Paul can’t win this fight. No Washington politician can win this fight. The only people who can win this fight are you. The only way we win this fight is if the American people rise up in overwhelming numbers and demand our elected officials to do the right thing and stand for principle.”

This is a shopworn tactic: Stake out a ludicrous position, insist you are serious and then blame other pols (the sober ones) or even the public when the whole thing collapses. Really, do they imagine voters are so dim as to not realize this is purely an exercise in self-promotion and a fundraising technique?

Meanwhile, Rubio plugs along, trying his best to maintain his sincerity. His argument is attractively simplistic but illogical: Obamacare is bad. September is the best time to stop it. We will threaten to shut down the government to do it. (He is so sincere you wonder if he is actually hopelessly naïve.)

Actually, the best time to shut it down is after the state exchanges begin to collapse and/or fail to meet the Oct. 1 deadline and panic descends among Democratic ranks. And of course, Rubio and his colleagues can’t get what they want (even if other Republicans jump off the cliff with them and even by threatening to shut down the government). Obama will simply say no.

This is not an advertisement for mature leadership. That is why other GOP senators and House leadership is remaining mum.