Christopher Howard of Vacaville, Calif., waves to passing motorists during a Flag Day Rally sponsored by The Vaca-Dixon Tea Party Patriots and the Vacaville Elks Lodge No. 2648 on June 14. (AP Photo/The Reporter, Joel Rosenbaum)

In announcing her presidential bid earlier this month, Minnesota Rep. Michele Bachmann described the tea party this way: “It’s made up of disaffected Democrats. It’s made up of independents. It’s made up of people who have never been political a day in their life.”

But, political rhetoric aside, is there really such thing as a Tea Party Democrat?

The answer is yes, Tea Party Democrats do exist. But there’s also little reason to believe they have had a major role in the movement or in American politics.

Republican leaders have gone out of their way, of late, to make the argument that the tea party is more than just group of (somewhat) disaffected GOPers.

In March, former Republican National Committee Chairman Michael Steele said that there are “many Democrats, conservative Democrats, in the tea party movement.”

And at a presidential forum in New Orleans in June, Bachmann estimated that the tea party was comprised of 60 percent Republicans, 20 percent independents and 20 percent Democrats.

Democrats, meanwhile, tend to dismiss the tea party as a bloc of voters who would vote Republican anyway.

So who’s right?

This answer lies, as it often does, somewhere in the middle.

Polling has never shown Democrats to be 20 percent of the tea party, as Bachmann claims, but it has shown there is a significant number of Democrats in the movement. Often, the number is somewhere around 10 percent.

The GOP polling firm the Winston Group last year showed 13 percent of tea partiers were Democrats, while Gallup put the number at 15 percent. On the lower end, the number was 9 percent in a Targetpoint poll, but just 4 percent in a CNN/Opinion Research poll.

More recently, a poll for Resurgent Republic, a Republican-aligned conglomerate of GOP pollsters and consultants, showed 11 percent of those who viewed the tea party favorably were Democrats. (That’s not an ideal measure, of course, since one need not be a tea party member to view it favorably.)

So who are these tea party Democrats?

Republican pollster Dan Hazelwood said that just as some Democrats moved to the GOP because of social issues in recent decades, some are now moving to the tea party because of fiscal issues.

“They have the same populist point of view of the rest of the tea party movement,” Hazelwood said. “Their ideal would be a Dennis Kucinich-type who was anti-spending and for budget austerity. So they are people who are adrift on the left because of spending and on the right because of social issues.”

We have yet to see a formidable Democrat emerge as a tea party candidate, though there has been some intermingling between the two camps.

The Tea Party Express last cycle endorsed Blue Dog Democrat Rep. Walt Minnick (Idaho) in his unsuccessful reelection bid (Minnick wound up rejecting the endorsement), and former Democratic nominee Jack Davis ran on the “Tea Party” line in the recent New York special election, taking 9 percent. (Davis had run three times before as a Democrat and seemed to have a flexible ideology — at best.)

There was also a tea party supporter who ran a meagerly funded primary campaign against Rep. Kathy Castor (D-Fla.) in 2010, taking 15 percent of the vote.

Given that almost all of the tea party candidates were running under the GOP banner, then, we might have expected those who consider themselves as Tea Party Democrats to vote Republican — creating a larger number of crossovers than typically seen in an election.

But according to exit polls, the 7 percent of Democrats who voted for Republicans in 2010 was completely in keeping with past results (10 percent of Democrats voted for John McCain for president in 2008, and 7 percent of Democrats voted Republican in 2006, for example). And given that 2010 was a wave year for Republicans, it would have been an ideal year for more Democrats to cross over.

In other words, it’s very hard to measure what, if any, impact the Tea Party Democrats had on the 2010 election; the big shift was among independents, who swung for Republicans by a 19-point margin.

In the end, the Tea Party Democrat is still a pretty odd creature, rarely found and without any considerable influence in electoral politics.

So, while Republicans can accurately point out that the Tea Party Democrat does exist, the movement remains almost entirely composed of GOP-aligned voters and disaffected — and conservative-minded — independents.

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