What a difference a year makes. Last summer, both Republicans and Democrats considered the idea of a tea party a joke. Tea partiers were good at raising hell at town meetings, but they were too scattered and too undisciplined to be taken seriously.

No longer. This summer, although still scattered and with no official organization or leader, the tea party has emerged as a significant political force. Across the country, its supporters have battled for the heart and soul of the Republican Party – and won almost every contest.

Indeed, in six states, tea partiers have stolen the Senate nomination from establishment Republican candidates. In Utah, Mike Lee ousted incumbent Sen. Robert Bennett. In Kentucky, Rand Paul trounced Mitch McConnell’s handpicked candidate, Trey Grayson. In Alaska, Sarah Palin-backed Joe Miller upset incumbent Sen. Lisa Murkowski. Ken Buck knocked out former Lt. Gov. Jane Norton in Colorado. Sharron Angle beat out front-runner Sue Lowden in Nevada. And now, in Delaware, Christine O’Donnell has toppled Rep. Mike Castle, who’d been supported by the entire state and national Republican hierarchy.

Flush with victory, tea partiers are celebrating what they call the “de-rinofication” of the Republican Party (i.e., getting rid of “Republicans in name only”). But me thinks they pop the champagne corks too soon. What good is it to win the primary if you thereby set yourself up to lose in November? And, let’s face it, most of these candidates are so far out on the fringe they’re likely losers.

The one exception, Utah, is so red it doesn’t matter how extreme a candidate is. Not so for Alaska. Palin’s handpicked candidate, Joe Miller, wants to phase out Social Security and Medicare, abolish the federal Department of Education and cancel all unemployment benefits because, he says, they’re unconstitutional. Suddenly, in a state they’d previously written off, Democrats have a real shot with Scott McAdams, mayor of Sitka.

Same in Kentucky. It’s about as red as you can get, but are Kentucky voters really ready for Rand Paul, who proposes shutting down the federal Department of Education, commerce and energy and calls Medicare “socialized medicine”? He’s so anti-government he wants to abolish the income tax, repeal the Americans with Disabilities Act and is still not sure he would have voted for the 1964 Civil Rights Act. His extreme positions give Democratic Senate candidate Attorney General Jack Conway a realistic chance of taking a Republican seat.

In Colorado, Democratic incumbent Michael Bennett was considered political dead meat until tea partiers won the Republican nomination for Ken Buck, who joins the cry for abolishing the Departments of Energy and Education and began his campaign by calling for repeal of the 17th Amendment, which established direct election of U.S. senators by popular vote, and a return to the “good old days” when state legislatures, not voters, chose members of the U.S. Senate.

Majority Leader Harry Reid got a similar break. Talks of his political demise ceased once Nevada Republicans rallied behind Sharron Angle, who makes Sarah Palin sound almost rational. True to form, Angle wants to phase out both Social Security and Medicare and pull the United States out of the United Nations. She’s also disturbingly asserted the people’s rights to “those Second Amendment remedies” if they fail to get government reforms they demand.

In the “how wacky can you get?” department, however, even Sharron Angle takes a back seat to Christine O’Donnell. A typical tea partier, she calls for repealing the health-care reform law and federal funding for stem-cell research and AIDS prevention. But, as a pro-abstinence conservative Christian crusader, she also advocates opposition to any sex outside of marriage and opposition to masturbation. Which is what I was taught, growing up a Catholic in Delaware, but may not be a winning political issue statewide.

Democrats would make a big mistake in taking any of these races for granted. In addition to pointing out the tea partiers’ extreme positions, they must also work hard over the next eight weeks in providing a stronger, saner alternative. But there’s no doubt that, in at least four out of six states, Republicans have given Democrats an opportunity to snatch victory from the jaws of defeat.

O’Donnell’s victory, in fact, prompted Karl Rove to exclaim that Republicans had destroyed their last best hope of regaining control of the Senate. Which, in turn, prompts me to utter four words I thought would never cross my lips: “Karl Rove is right.”

Note: Read our discussion guidelines before commenting.