One of the least attractive legacies of Barack Obama will be the way he empowered freshman senators to believe they were only one or two good speeches away from the presidency.

Right now, the show horses of the United States Senate are Rand Paul of Kentucky, Ted Cruz of Texas and Marco Rubio of Florida. All preparing for a 2016 presidential bid. All making visits to Iowa. They’re the new faces of the Republican Party. Really, really new. The three of them have an average age of 45 and an average tenure in Washington of 1.9 years.

And all three are currently in the news for their efforts to get Republicans to promise not to vote to fund the government this fall unless the president cancels Obamacare.

"I think it’s the dumbest idea I’ve ever heard," said Senator Richard Burr of North Carolina, speaking on behalf of a large number of Republicans who regard the idea of shutting down the government with horror and who are never going to be mentioned in a Quinnipiac presidential poll.

Rubio, Cruz and Paul weren’t the first senators to promote the shutdown idea. But they’re the ones with the national names, in a party that’s got a crush on crazy.

They’re very different. Marco Rubio is a Cuban-American with a background in Florida politics who keeps bouncing and hedging in a desperate attempt to look like a bipartisan statesman who is — wait! wait! — also a right-wing true believer. He was a key negotiator behind the Senate immigration reform bill, which he now says he will not lobby for in the House.

Ted Cruz is a Cuban-American with a background in law whose father used to tell him, "You know, Ted, you have been gifted above any man that I know, and God has destined you for greatness."Rand Paul is the libertarian son of former Congressman Ron Paul with a background in ophthalmology.

Paul and Cruz in particular tend to drive other Republican senators nuts. We probably have them to thank for the return of the pre-2008 version of John McCain, who would rather be anyplace than in a party caucus listening to Ted Cruz give a speech. Asked by The New Republic whether he would support Rand Paul or Hillary Clinton for president, McCain laughed and said, “It’s gonna be a tough choice.” Actually it wouldn’t. If Rand Paul got nominated for president, McCain would be the honorary national chairman of Republicans for Hillary.

The ones who aren’t irate are terrified. John Cornyn of Texas, the No. 2 Republican in the Senate, is a clubhouse sort of guy, but he’s trying desperately to get renominated without a right-wing primary opponent. So far, Cornyn has signed onto the letter promising to go along with the government shutdown threat, taken his name off the letter and then burrowed into the ground, where he will emerge in September, unless he sees his shadow.

And imagine being Mitch McConnell, the senator previously known as “powerful minority leader.” McConnell already has a Tea Party opponent back in Kentucky, and he’s had to grovel to Rand Paul for support. (“Particularly important and means a great deal.”) His campaign manager is the junior senator’s nephew. Both Paul and Cruz spend their careers violating the old party dictum about never speaking ill of a Republican. Asked about speculation that Gov. Rick Perry might run again for president, Paul grinned and said there were three good reasons Perry could succeed: "You know, Texas is a big, successful state. He’s a long-term governor. I can’t remember the third one, but, uh.”Cruz told Glenn Beck that Republicans who didn’t like his idea were “scared.” He called the House’s votes to defund or dismember Obamacare “empty,” thus casting aspersion on the lower chamber’s entire reason for existence.

The fight between the Shutdown Trio and their colleagues is not about the Affordable Care Act, which virtually every Republican in Congress loathes and gives speeches about constantly, even when the topic under consideration is supposed to be oil drilling or the next secretary of labor.

The fight is over whether the fortunes of the party would be improved if people connected it to the sudden closing of the national parks and the local passport office. “We’ve been down that road,” said Senator Saxby Chambliss on MSNBC. “We shut down the government ...and we got our butts kicked over shutting down the government.” Chambliss is 69 and about to retire. Nobody is ever going to invite him to give the keynote address at the Iowa Republican Party summer picnic.

“The sort of cocktail chatter wisdom that ‘Oh, the shutdown was a disaster for Republicans’ is not borne out by the data,” Cruz said. The Democrats are sort of horrified and sort of enthralled by the whole drama.

“Give a call to Newt Gingrich. He’ll return your phone calls. Ask him how it worked,” suggested Majority Leader Harry Reid. Gingrich, who led the House during the last government shutdown in 1995, was busy touring the Peoria Zoo, where he admired a parrot.