WASHINGTON — Don’t count Ron Paul out.

That’s the warning from election experts watching the race for the GOP’s nomination, who say that Paul has the money and fiercely loyal support to stage an upset at the crucial Iowa caucuses.

“There’s a strong loyalty to him,” Iowa pollster Ann Selzer told The Post.

“You can’t write him off. You have to say he’s building the kind of organization that can succeed.”

And finishing strong in that contest could help him rake in more votes in later primaries, she said.

The Texas Republican has a strong ability to raise campaign cash, has been on the air with more than $1 million in TV ads in Iowa and is building a nationwide organization.

The latest Iowa State University poll has Paul at 20 percent, second only to Herman Cain.

But two other metrics show that Paul leads among voters who say their minds are made up, and is tied with ex-Massachusetts Gov. Mitt Romney among people who say they would definitely show up on caucus night.

Paul is also getting more attention in the debates.

In Wednesday night’s contest, Paul was at the center of many of the foreign-policy discussions and got to speak for a total of nearly 10 minutes, nearly as much time as Romney.