Protest movements sometimes have perverse effects, hastening outcomes they don’t want.  Tuesday’s Republican Iowa caucus has to be scored as a disappointment for the Tea Party, perhaps a sign of its dissolution.

The Tea Party, an alliance between populist and plutocrat dissatisfaction with President Obama, coalesced just after Obama took office, and focused early on opposition to his effort to reform and extend health insurance in the United States.  Now, another irony of American politics, Obama’s most likely opponent in the general election signed the legislation on which Obama’s health care reform is based.  Mitt Romney, who won a narrow victory in the Iowa caucus, is preparing to run a campaign in which he will advocate taking health insurance away from tens of millions of Americans–but not the residents of Massachusetts, whom he’s already taken care of.  Tea Partiers, and many Republicans, are understandably uneasy about this prospect.

But it’s worse than that.  The Tea Party captured the imagination of conservative activists around the country, and was an immense aid in firing up Republican voters in 2010.  It also pushed the focus of American political debate to taxes, debt, and deficit, on terms that were initially very unfavorable to President Obama and the Democrats.  The Tea Party succeeded, in part, by putting social issues on the back burner.

But Republican presidential hopefuls seeking Tea Party support sought to distinguish themselves on the vigor of their commitment to stopping abortion and gay marriage.  The Tea Party buoyed up the aspirations of several prospects who proved far from ready for presidential prime time, crowding out more mainstream–and credible–candidates for office.  Thus, the Republican field came to include Michele Bachmann and Herman Cain, but not Tim Pawlenty or Mitch Daniels.  Of course, Mitt Romney, who had been raising money, organizing, and planning, since well before the Tea Party, survived.

Republicans who were dubious about Governor Romney, including Tea Partiers, flirted with a series of alternatives who, for various reasons, were found wanting: Bachmann, Governor Rick Perry, Cain, former Speaker Newt Gingrich.  A longer list could include flirtations with Sarah Palin and Donald Trump as well.

Former Senator Rick Santorum, mostly due to his profile and politics, avoided much affection and attention, until he was the last potentially viable alternative to Romney.  To the extent he’s a Tea Partier, however, it’s as a social conservative, not really a deficit hawk or anti-tax crusader.  At this writing, it’s hard to imagine that Senator Santorum will withstand more than a few weeks of scrutiny.

And what about Rep. Ron Paul, a committed libertarian with a provenance that extends well before the current Tea Party?  His isolationist foreign policies and generally consistent hands-off approach to social issues (except abortion) represent one wing of the early Tea Party.  But they also challenge the orthodoxy of most of the Republican Party.  He brought energy and new voters to the caucuses, but there appears to be a real ceiling to how much his support can grow–and he’s close to that ceiling now.

If Rep. Paul’s support does grow, be sure that mainstream Republicans will go after him–just as some of the Republican hopefuls already have.  They will charge him with a willingness to ignore Iran pursuing a nuclear weapon and supporting the legalization of drugs–and he’ll plead guilty.

And in doing so, they will forsake the Tea Party movement for a restoration of the Reagan Republican coalition.  But the alliance of White religious social conservatives and economic conservatives comprises a smaller share of the electorate today than it did in the 1980s.

So, the successful mobilization of the Tea Party has produced exactly what most Tea Partiers didn’t want.