WASHINGTON — When the National Tea Party Convention concluded in Nashville, Tennessee this weekend it was clear that the Tea Partiers were propelled by two competing claims — a principled commitment to fiscal conservatism and a serious case of what some are calling “The Obama Derangement Syndrome.”

The Tea Party crowd carried signs comparing President Obama to Hitler and Communists, while proclaiming themselves patriots. One speaker insisted that Jesus’ birth was better documented than President Barack Obama’s.

Former congressman Tom Tancredo even accused the president of being a “committed socialist ideologue” and proposed a civic literacy test for voting.

This had led some observers to say that their Tea Party extremism will ultimately lead the movement to self-destruct unless it is clearly repudiated.

While Tax Day 2009 Tea Parties attracted some 300,000 people nationwide, this convention accommodated just 600 people, who paid nearly $500 each for the privilege of attending the populist conference and help to pay Keynote Speaker Sarah Palin’s $100,000 speaking fee.

And although it was Palin who hogged the headlines — that is, until the underdog New Orleans’ Saints won the Superbowl Sunday night, some observers say it was still a good weekend for Obama — exactly because Palin grabbed the headlines. A poll taken late last week gave the hockey mom from Wasilla a five-point lead over the next most popular contender for the 2012 Republican nomination — Mitt Romney, a former Massachusetts governor. Her speech to the Tea Party convention was covered by every network and newspaper from the liberal mainstream media that the Tea Party movement affects to despise.

Palin told the National Tea Partiers on Saturday night that “America is ready for another revolution,” and that the Tea Party movement would lead it.

Her attack on Obama’s record on national security was taken seriously by pundits, who agree terrorists do not deserve due process in the US courts, but her support for radical conservative challengers in Republican primary elections will have sent shivers down many a spine in the party’s national leadership.

A serious Palin run for the White House is now a real possibility, not just the fantasy of a disaffected minority.

That should please Obama’s staff and supporters immensely, because some political observers say Palin represents nothing but trouble for the Republicans, for two main reasons: First, she has already shown she can split the conservative vote and thereby lose seats to the Democrats by backing hard-right candidates over moderates favored by the Republican leadership.

Second, no potential Republican presidential nominee is guaranteed to send independent voters flocking back to the Democrats more than Palin.

She is a hard-line social as well as fiscal conservative, but more alarmingly for the independents, she still lacks much of the basic knowledge of the world they consider a prerequisite for competence. She said on Sunday: “I’m never going to pretend I know more than the next person.” Asked on “Fox News Sunday,” about a recent poll that showed her topping a field of potential Republican candidates by 5 percentage points, she said that she would run for the 2012 GOP nomination “if I believed that that is the right thing to do for our country and for the Palin family.” Whatever Palin’s intentions, it does her no harm to leave her options open, said one Republican strategist. “This far out from the election, it would be insane for her to rule out running even if she has no intention of actually doing it,” Todd Harris said in an interview Sunday. “As long as the possibility is out there, it helps add to her cachet. It adds to her political power. And, frankly, it helps fill seats at rallies and sell books.” As for the Tea Party movement, some political cynics tell us to remember what the author Eric Hoffer warned in his book “The True Believer:” “Every great cause begins as a movement, becomes a business and eventually degenerates into a racket.”