Now that the three-ring circus of Donald Trump's endorsement has passed, the real action in Nevada is almost here, as 28 Republican delegates are up for grabs on Saturday in the Silver State.

Polls again indicate that Mitt Romney has the edge in Nevada, with the Las Vegas Review Journal giving him a twenty point lead over Newt Gingrich.

A new poll from Public Policy Polling also has a big edge for Romney as well.

But how much should we believe these polls?

"I've had a lot of trepidation about polling the caucuses in Nevada, Minnesota, and Colorado in the coming week," said PPP CEO Dean Debnam on the company's web site.

"Caucuses are particularly hard to poll and for whatever reason the state of Nevada itself is hard to poll," he added.

Let's look back four years ago, when Romney won the state with over 51% of the caucus vote. Which polls got that?

Bzzzzzzzzt.

Your answer - no one.

"In 2008 none of the polls there came within 22 points of Romney's margin of victory," said Debnam.

And that makes you wonder about any polls in Nevada, along with Colorado and Minnesota, two other caucus states that start their work next week.

"I'm just going to say up front that these caucuses are exceptionally difficult to poll and that's why you may not see too many pollsters take a stab at them," said Debnam.

"Turnout is very low and it's hard to figure out who's really going to vote and who's not."

Unlike Florida's "winner take all" formula, Nevada does things a little differently.

For every 3.57% of the vote you get, you claim one delegate.

So, if Romney gets 50% of the vote, he will lock up 14 - half of the delegates from the Silver State.