Salena Zito

The best way to forecast the Republican primary for Florida’s U.S. Senate seat would be to quote Winston Churchill: "It is a riddle, wrapped in a mystery, inside an enigma."

Going Rogue by Sarah Palin FREE

Basically, the race defies conventional wisdom.

A few months ago, Gov. Charlie Crist was in the catbird seat. Hugely popular, he was set to win the 2010 GOP primary in a landside over former Florida House Speaker Marco Rubio.

Last week, a new Rasmussen poll of likely Republican voters showed Crist and Rubio tied, each with 43 percent of the vote.

The political riddle is why Rubio cut Crist’s lead by more than half. Is it that Rubio is gaining, or that Crist is slipping?

“I think it is a combination of both,” Rubio said, in between his son’s school play and campaigning. “People are starting to realize they have a choice now, and the polls show they are considering outside of the establishment.”

Part of Rubio’s gain is natural: Crist is the better-known politician – but once a challenger gets enough financing to make themselves known, the challenger usually is able to cut into a big lead.

If the earth stands still and conditions stay current – and that is a big “if “ – Crist likely will win the nomination and probably the seat. But when was the last time the earth stood still?

Two things are going on nationally that make the Crist-Rubio race a bellwether for just about every primary across the country.

One pertains to schisms within parties – and a bigger schism exists now among Republicans than among Democrats. Although Democrats are actually less cohesive and more varied than Republicans, they are much less likely to want to commit fratricide.

The other thing is what ultimately decides primary elections: a fired-up base. Unfortunately for Crist, he has become the national poster-child for party discontent; his collapsing poll numbers put that in perspective.

If national conservatives decide this race is where they make their stand against moderates, a lot of momentum, focus and money will follow.

For Republicans this will be a battle between pragmatic instincts and political purity.

The 23rd Congressional District race in New York was an excellent example of this. Party leaders in the proverbial smoke-filled room picked the kind of candidate who might have won the seat; the base backed the guy likely to lose.

Salena Zito

Salena Zito is a political analyst, reporter and columnist.