In a broad slap at the the uncompromising stands of conservative Sens. Ted Cruz, Rand Paul and Mike Lee, the liberal Brookings Institution's top political scholar charged this week that the Tea Party trio are leading the Republican Party to disaster and minority status.

Thomas Mann said that their stubborn style of politics that has been rapped even by some mainstream Republicans, notably  self-styled "maverick" Sen. John McCain, will lead to a voter revolt that will elect more Democrats to the House and Senate, the presidency, and eventually have the remaining GOP members begging to do business with Democrats.

At an event to discuss the current state of politics in Washington, Mann said change is coming that will lead Congress back to being more bipartisan and less confrontational, but only after the GOP crumbles.

"If I'm correct," he said, "the route is with them being led by Ted Cruz, Rand Paul, Mike Lee, the Republicans will decline, They will not regain the Senate, they will lose the next presidential election and they will lose the House at some point. The majorities may be large enough for Democrats to govern, even in the Senate. Under those circumstances, if that happens, some Republicans will feel obliged to do business with them and you will begin to set a new dynamic."

He said the solution to fixing Washington has only two routes: "Either a dominant one-party, Democratic system to get something done," he said, or a "situation where the Republican Party returns to its sanity and to a position of problem solving."