The American primary system is a grueling marathon and while in rules out many decent candidates, it also weeds out candidates who cannot handle pressure.
Texas Gov. Rick Perry is facing a crucial moment in this campaign after he was savaged at the Tea Party Movement debate. This was not like last week's debate at the Reagan library, where Mitt Romney may have won on points, but Rick Perry delivered the soundbites that honed in on the voters.
The Florida Tea Party debate saw Perry attacked from both the left, by Romney and Jon Huntsman, and from the right by Michelle Bachmann, for whom the debate was a 'do or die' moment.
After the first California debate, it appeared that Rick Perry had disposed of Michele Bachmann and had thus united the Republican conservative base against Mitt Romney. As the conservatives are the majority of Republican primary voters, this accounted for Perry's widening lead in the polls.
But Perry found himself booed by the Tea Party audience on the immigration issue. He was also hurt on the vaccination issue that Texas administered to 12 year olds including the whiff of scandal. On the Social Security issue he may be right in saying that for the next generation the program is probably unsustainable, but he failed to assure the viewers that he had a credible alternative.
The Florida debate raised questions over whether Perry can perform effectively in a debate. If he gets pummeled by Romney and Bachmann, it raises doubts about how he would fare in a debate against Barack Obama.
Republican strategist Karl Rove and Perry may have blood between them, certainly after Perry slammed into Rove at the California debate, but Rove represents the Republican establishment.
Perry's strength up to now has been the impression that he could enlist the Tea Party enthusiasm and still remain acceptable to the Republican establishment.
Even in the afterglow of the successful 2010 midterm elections, the establishment and Tea Party have issues between them. The Tea Party was convinced that it had energized the Republican Party; the establishment rejoined that the Tea Party's 'rule or ruin' tactics had sabotaged Republican chances in eminently winnable senate seats in Delaware and Nevada, ruining Republican chances to tie or control the senate.
The establishment is wary that Perry could become another Sharon Angle, the unsuccessful Tea Party Nevada candidate, on the national stage, and therefore it is much more comfortable with Romney.
Perry cannot take solace in the usual politician's line that if attacked from both sides, he must be doing something right. That is fine for a politician once he has been to elected to office, but not for a candidate.
He must show that he can bone up for a debate and go the distance without sagging. Otherwise, Romney will nibble away at the center and Bachmann will erode his conservative support.