As was proven after this last election, when the Republican caucus had their chance to vote for new leadership, they failed. This likely condemns the US to having another Democrat as POTUS, as the current Republican leadership is determined to only permit one of two losers from getting the nomination: Bush or Romney, both of whom will lose to Hillary.
This means that it will likely take conservatives three more elections to cull enough of the Republican leadership to take over the party. And in that time, the leadership will not give Ted Cruz any power in the senate, they will not support him in the elections, and they will fight against any campaign he launches for POTUS.
And six years is a minimum. Even odds are that it will take longer than that.
However, if either Bush or Romney actually win, they could appoint Ted Cruz to the SCOTUS. They would do this simply to get him out of the senate, and the senate would likely oblige. But it would catapult him to a place of extraordinary power and influence in an assuredly conservative court.