What If The Tea Parties Follow Through?

Beinart thinks they will get crushed at the ballot box:

Bush didn’t reduce spending on popular middle class entitlements; he forced through a prescription drug benefit that increased such spending by $500 billion over ten years. In 2005, flush with his reelection win, he reversed course somewhat and tried to partially privatize Social Security. The result: a political defeat from which his presidency never fully recovered.  

Which brings us to the Tea Party, many of whose activists seem genuinely dedicated to slashing government spending (except on the military, of course) and making the party of Reagan and Bush, once again, the party of Goldwater and Gingrich. Maybe this is one reason the GOP establishment is so scared? Over the last half-century, the Republican Party has been, at times, a genuinely anti-government party and, at times, a politically successful party. But it’s never been both at the same time. Once this fall’s elections are over, I suspect the Tea Partiers will begin learning that, the hard way.

But the whole point of having a majority is to get legislation passed. If the Tea Partiers were able to zero out the long-term deficit, their getting booted out of office a couple years hence would be of little consequence to them, would it? They're not Republicans, after all. Or are they?