RAYMORE, MO. — Talk about a nasty divorce. In an announcement last month that left Missouri politicos agape, state Sen. Chris Koster, a rising Republican star and chairman of the Senate's GOP caucus, abruptly declared himself a Democrat.
Not only did Koster join the marginalized minority party in Missouri, but he did so with a thundering speech that lambasted his former colleagues as ignoring the needs of their constituents and slavishly following the dictates of "religious extremists."
The former prosecutor denounced several Republican positions he had once supported, such as steep cuts in Medicaid coverage and subsidized family-planning programs.
But Koster reserved his harshest criticism for GOP efforts to overturn a voter-approved constitutional amendment that protects embryonic stem-cell research in Missouri.
"The Republican desire is to criminalize early-stage stem-cell research in our state," Koster said in a speech he repeated three times as he hopscotched across the state. "Go to Boston for your Nobel Prize; come to Missouri for your leg irons. And the Missouri Republican Party not only tolerates this lunacy, but embraces it," Koster said.
Days later, one of his staffers updated his website -- by deleting a photo of Koster shaking hands with Vice President Dick Cheney.
Koster's decision stunned Republicans here in his district just south of Kansas City and across this quintessential swing state. "There's no precedent for it in the state of Missouri," said GOP consultant Paul Zemitzsch.
But the move sounded like deja vu just across the state line in Kansas.
Three prominent Kansas Republicans moved into the Democratic column in late 2005 and 2006, voicing similar concerns about the influence of social conservatives. One of those defectors was elected attorney general. Another -- who once chaired the Kansas Republican Party -- now serves as lieutenant governor.
Political analysts don't expect a cascade of party-swappers in Missouri. As political scientist David Webber put it: "I'll be darned surprised if anyone follows [Koster's] example."
But they say the move does point at how effectively social and religious conservatives dominate the Republican Party across several Midwest states -- and how frustrating that can be to self-styled moderates who would prefer to focus on economic issues.
"That's been true for a decade," said Webber, a professor at the University of Missouri at Columbia.
Missouri elder statesman and former U.S. Sen. John C. Danforth last year wrote a book on the subject. "Faith in Politics" called on the GOP to shake free of the religious right. Danforth is now trying to translate those words into action by leading a national coalition of GOP moderates called the Republican Leadership Council.
Koster knows that many in Missouri would have preferred it if he, like Danforth, had stayed with the GOP despite his differences. "It's a disappointment to lose him," said former state Sen. Betty Sims, who had her own battles with the religious right but remained Republican.
But after three years of feeling out of sync with his own party, Koster, 42, said he couldn't take it any longer.
The final straw, he said, came this spring when his colleagues overturned a state law requiring public schools to give students comprehensive, medically accurate information on sexually transmitted diseases and birth control. Districts may now focus exclusively on abstinence.
"I knew at that moment," Koster said. "For me, leaving was the right, the moral thing to do."
Skeptics -- and there are plenty -- point out that Koster voted for the abstinence-only provision that he now says is so troubling. (He says that's because the bill included other programs he supports, such as funding to encourage pregnant women to consider adoption instead of abortion.)
These critics see Koster's switch as opportunism, a way to bolster his expected candidacy for state attorney general in 2008 -- a year many pundits expect will be good for Democrats across the board.
"Any time you jump to the other side of the ship to make a gain and leave your friends behind. . . it's hard to respect someone like that," said Tom Circo, 54. A Republican, Circo sells insurance here in Raymore, a town of 16,000 in Koster's western Missouri district, which stretches from the suburbs of Kansas City into farmland.
Koster responds that he jumped from the fourth-ranking GOP position in the state Senate -- with a cushy office and a chance at a still-higher leadership role -- to become the lowest-ranking Democrat in the state Senate. He will face stiff competition in the Democratic primary for attorney general. The governor, a Republican, has urged him to resign his Senate seat.
He's hated by many on the right, distrusted by more than a few on the left. And to top it all off, he has opened himself to charges of flip-flopping not only on party affiliation but on key positions. When he made the switch, he announced he was no longer "pro-life" but would henceforth support legal abortion.
So if he was trying for political gain, Koster jokes, he pretty well botched it.
John Willis, 73, disagrees.
A voter in Koster's district, he said he didn't believe in blind loyalty to either party -- and he was glad to have a state senator who apparently felt the same.
"If he has the guts to do that, he must believe in it," Willis said. "And that's what we want in our politicians, isn't it? People with the guts to stand up for what they believe in."