Updated: 10:56 p.m.

The Alaska Senate race grew more interesting Friday night as GOP Sen. Lisa Murkowski announced she is launching a write-in campaign for re-election — a last-ditch effort to retain the seat she has held since being appointed by her father, former Gov. Frank Murkowski, in 2002.

The announcement sets up a three-way race between Murkowski, Democrat Scott McAdams and Republican Joe Miller, who defeated Murkowski in the Aug. 24 primary by 2,006 votes and has the full support of the Senate Republican leadership.

Minority Leader Mitch McConnell (Ky.) made clear that the Senate GOP Conference has moved beyond the primary fight and embraced Miller.

“Senate Republicans informed Lisa Murkowski that we will respect the will of the voters in Alaska and support the Republican nominee, Joe Miller,” McConnell said. “I informed her that by choosing to run a campaign against the Republican nominee, she no longer has my support for serving in any leadership roles, and I have accepted her letter of resignation from Senate leadership. Lisa has served her state and our party with distinction, but Republicans acknowledge the decision Alaskans made and join them in support of the Republican nominee, Joe Miller — the next Senator for Alaska.”

But Murkowski was defiant.

“Alaskans deserve a fighter in the United States Senate who will always stand up for Alaska, who understands our great potential and has the experience, the respect and the seniority to accomplish that,” she said. “I am that Senator.”

Murkowski took a shot at Sarah Palin (R), saying she, not the former governor, is “one Republican woman who won’t quit on Alaska.”

She admitted that she did not go after Miller enough in the primary, something the national party had pushed her to do. But she signaled that was about to change.

“We made some mistakes,” Murkowski said. “When he swung, I didn’t swing back. Well, ladies and gentleman, the gloves are off.”

Murkowski is wading into nearly uncharted waters. Just one person has been elected to the Senate by write-in: Sen. Strom Thurmond, the late South Carolina Republican, in 1954.

The political world has been abuzz since Murkowski conceded the GOP primary more than two weeks ago in a stunning loss to Miller, an underfunded tea party favorite and friend of Palin’s. Rumors immediately swirled that the Senate Republican Conference vice chairwoman was seeking avenues to get onto the general election ballot.

Other than waging a write-in campaign, Murkowski’s only opportunity to run would have been as the nominee for the Libertarian Party, the only party other than the Democrats or Republicans with a candidate on the ballot. She explored that possibility, sitting down with the party chairman and its nominee, David Haase. However, neither the party nor Haase was amenable to making the switch.

The National Republican Senatorial Committee has stepped firmly behind Miller since Murkowski’s defeat, dispatching top party campaign strategist Terry Nelson to Alaska and pledging the maximum amount allowed in coordinated funds.

“Republican primary voters spoke when they nominated Joe Miller in Alaska, and I am deeply disappointed in Sen. Lisa Murkowski’s decision to ignore that clear message and wage a write-in candidacy,” NRSC Chairman John Cornyn (Texas) said. “The NRSC stands firmly behind Joe Miller’s nomination, and we will ensure that he has all of the resources that he needs in order to win this November.”

Murkowski attempted to get in front of an argument she said her opponents will likely pick up. Murkowski had said she would accept the outcome of the primary election, but said Friday, “I regret that I made that statement.” She said that was not enough to keep her from running.

In a statement to reporters, the Democratic Senatorial Campaign Committee chalked up Murkowski’s entrance into the race as the latest in a string of implosions that have riled the GOP throughout the primary process.

“Lisa Murkowski’s decision to mount a write-in campaign is just the latest example of the Republican Party cannibalizing itself,” DSCC spokeswoman Deirdre Murphy said. “From the tip of Florida, to the beaches in Delaware, all the way to the islands off Alaska, the Republican Party heads into November with deep and serious divisions.”

While Thurmond is the only Senator ever elected by write-in, researchers at the University of Minnesota reported recently that there have been eight write-in campaigns for statewide office in Alaska since 1958, when the state elected its first two Senators. The most support a candidate ever received was 27 percent in the 1978 gubernatorial election.

Of course, with her name and résumé, Murkowski is no average write-in candidate, and this is no regular election year. While most write-ins have trouble finding a base of support, one Alaska source who has studied the electorate said there is a gaping hole in the middle of the political spectrum of voters between Miller and McAdams — a hole that Murkowski, who is more well-known and well-financed than most write-in candidates, could fill.

Also in her favor is state election law, which says voters do not need to spell the candidate’s name correctly — only that the intent of the voter is clear. Where that line is drawn will be something to watch.

Murkowski addressed that in her speech, saying, “Alaskans can’t figure out how to fill in an oval and spell M-U-R-K-O-W-S-K-I?”