REPUBLICANS IN VIRGINIA have been busy downsizing their tent for some time, mainly to their own detriment. Despite some success in state legislative elections, which owe much to gerrymandered districts, they have lost three straight elections for the U.S. Senate, two for the presidency and two out of the last three for governor. Not coincidentally, that anemic record coincides with the party’s sharp tilt to the right, which has made centrists feel unwelcome.

So it was that Attorney General Ken Cuccinelli II, a right-wing firebrand who has flirted with birtherism, denied climate change, bashed gays and waged a jihad against abortion, managed to outmaneuver Lt. Gov. Bill Bolling. By any measure, Mr. Bolling qualifies as a rock-ribbed conservative. But his pragmatic streak and mild demeanor paled in comparison to Mr. Cuccinelli’s flame-throwing appeal to tea partyers and other GOP radicals. On Wednesday, Mr. Bolling announced that he was bowing out of contention for the Republican nomination for governor.

Mr. Cuccinelli is an able politician and may mount a strong race for the governorship next year. Many Democrats worry about the potential weakness of their own likely nominee, Terry McAuliffe.

But the method by which Mr. Cuccinelli secured the GOP’s nod — by forcing a nominating convention instead of a primary, thereby excluding most of his party’s voters from the process — is a reminder of the internecine bitterness that has gripped the Republican Party in Virginia for years.

A conservative former governor, James S. Gilmore III, used the same stunt in 2008 to outflank a moderate rival, former representative Thomas M. Davis III, and lock up the GOP nomination for the Senate. For his trouble, Mr. Gilmore was demolished by the Democrat, Mark R. Warner, in the general election.

Limiting voter participation in elections is anti-democratic; it’s also frequently self-defeating. Republicans in a number of states, including Virginia, tried to obstruct voting by minorities, the young and the old by means of tougher voter ID rules in this year’s presidential elections. It didn’t work. But it certainly reinforced the impression that Republicans are hostile to those voters.

Republicans, like Democrats, are entitled to choose their nominees by any means they wish. But practicing exclusionary politics, as Mr. Cuccinelli has done in blocking a party primary, is likely only to leave a residue of resentment.

Little wonder that Mr. Bolling, in withdrawing from the GOP contest, has refused to endorse Mr. Cuccinelli.