ANCHORAGE, Alaska — U.S. Sen. Lisa Murkowski’s unusual write-in bid to hold on to her Alaska Senate seat appeared to be gaining steam in early returns Tuesday, but analysts warned the state could be in for a long, close ballot count whose official outcome may remain unknown for weeks.

With early-voted ballots and about 40 percent of the precincts tallied, write-in votes — most presumably cast for Murkowski — were leading with 39.44 percent. Tea Party Express-backed Republican Joe Miller was trailing with 34.62 percent, while Democrat Scott McAdams had 24.88 percent.

The early lead in write-in ballots suggested Murkowski had a chance of pulling off the first successful write-in campaign for the Senate since 1954. She appeared likely at least to meet the bar for triggering a full individual count of all write-in ballots.

Miller, a Fairbanks attorney, unexpectedly snatched the Republican primary in August from Murkowski, a moderate who was appointed to the seat by her father, former Gov. Frank Murkowski, in 2002 and was re-elected two years later.

Because of the apparent closeness of the race and the lengthy process of a write-in count, the official outcome could remain unknown until as long as Nov. 18. Counting of the bulk of about 42,000 absentee ballots won’t begin until Nov. 9, and individual scrutiny of write-in ballots would commence only after those are counted, said Gail Fenumiai, head of the state Division of Elections. Voter errors in writing in Murkowski’s name and other challenges could cut into her vote tally.

"In any case, Murkowski has demonstrated the ability to have her votes counted. So her prospects are looking very good and his (Miller’s) not so good," said Gerald McBeath, political science professor at the University of Alaska at Fairbanks.

McBeath said Murkowski needs to maintain a lead of 6 percent to 8 percent if she expects to win the race, to account for challenged ballots. "It’ll take two weeks for the write-ins to be counted. There’s going to be a great deal of interest, and of course the Miller campaign is going to be watching them very closely."

The race from the beginning has pitted two of Alaska’s most prominent politicians against each other: Murkowski, who was re-elected to the Senate in 2004, and former Gov. Sarah Palin, who beat the incumbent’s father for governor and who has put much of her political prestige in her home state behind electing Miller to Murkowski’s seat.

Although Murkowski is a moderate with ties to the business-oriented Republican Party establishment in Alaska, Miller struck a chord among religious and constitutional conservatives. He called for repealing the health care reform bill, phasing out Social Security and Medicare, and "making the tough, principled decisions" needed to roll back federal government "to the limited role anticipated by our founders."

Miller said he "unequivocally" opposes abortion, even in cases of rape or incest.

"He’s going to change Washington," Donald Dietz, a military retiree from Anchorage, said after casting his vote for Miller. "We’re thinking of our children and our grandchildren, and the debt they’re going to inherit — that’s the main thing."

But Murkowski, who had strong backing from Native Alaskan tribal corporations, the state teachers union and the United Fishermen of Alaska, mounted an unusual write-in campaign — bucking her own party apparatus — that managed to gain unexpected momentum despite predictions from most political analysts early on that she was bucking impossible odds.

"Eight weeks ago, they said, ‘Ah, they can’t do that in Alaska — they can’t do it.’ And we’re showing them how it is done," she told supporters Monday night.

Many who voted for Murkowski said the senator’s relative seniority and record of delivering aid for disadvantaged communities in Alaska would be big losses if her write-in bid failed.

"Two-thirds of the state economy (in federal aid) is inextricably tied to her. If we lose her, that will be a massive lost opportunity, and there’s no tangible means to get it back. No Murkowski, no gas pipeline," said Samuel Abney, a legal assistant in Anchorage who voted for the incumbent.

"Do you think Miller’s going to be considerate and diplomatic and carry out Alaska’s interests in Washington? All he can do is stand there and lambaste everybody who disagrees with him," he said.

The angst over Miller’s anti-federal stand injected new life into the campaign of McAdams, a former Sitka mayor and high school football coach who went from being a token Democrat in an election almost sure to re-elect the Republican incumbent to a serious contender who raised more than $1.2 million since the primary.

"I was a candidate with a staff of one who raised $17,000 in the primary and traveled from town to town using air miles," McAdams told his supporters at a pre-election rally, comparing the tempestuous, three-way campaign to a marathon in which he, apparently, was the tortoise.

"About two weeks ago we were at the 20-mile mark, and I could see the two people in front of me start to fatigue," he said.

McAdams insisted from the beginning that Murkowski, in her quest to climb up the ranks of the Republican leadership, had one of the Senate’s most conservative voting records.

"We all heard Joe Miller talk about how he’d like to repeal some of the finer points of the 20th century, whether it be Medicare or unemployment insurance or Social Security. … But Lisa Murkowski voted with (conservative South Carolina Sen.) Jim DeMint 87 percent of the time," he said, leading his supporters in a chant: "When Lisa votes no, she is just like Joe!"

Many Democrats admitted defecting to Murkowski, seeing her as the surer bet to stop Miller.

"I’m a Democrat, but I voted for Lisa," said Bill Bernath, a retired railroad worker. "I didn’t want Miller in there, and I didn’t think McAdams had a chance."