In any other election cycle, there would be no question that Sen. Lisa Murkowski was headed for an easy, blowout win over attorney and tea party favorite Joe Miller in the Aug. 24 Alaska Republican primary.

Her position as a senior Republican leader and her strong fundraising advantage — and Alaska’s partially open primary system, distrust of outsiders and historic tendency to embrace incumbency — would usually make her immune to an intraparty ousting.

But in the “lower 48,” as Alaskans refer to the continental United States, some Republican incumbents — and Democrats, for that matter — have found themselves in unexpectedly tough primaries, and a few have actually lost. None of this appears beyond Murkowski, the Senate Republican Conference vice chairwoman, who is acutely cognizant of the unpredictable political environment and isn’t taking her primary challenge for granted.

“Anytime you’ve got an opponent, you’ve got a race, so we’re taking it very seriously,” Murkowski said Thursday.

Miller has been endorsed by the Tea Party Express and former Gov. Sarah Palin, who defeated Murkowski’s father in the 2006 GOP gubernatorial primary. Murkowski is taking the Fairbanks Republican seriously enough that she plans to endure the 20 hours round-trip travel time to fly home Friday and spend about 36 hours on the ground campaigning before she heads back to Washington, D.C., for votes.

Murkowski closed the second-quarter fundraising period with $2.4 million in cash on hand, dwarfing Miller’s $124,384. Of that, $104,000 consists of a personal loan Miller made to his campaign. But Miller insists that Murkowski’s war chest will go only so far in Alaska’s inexpensive media market before her ads risk oversaturation, while arguing that his campaign volunteers are more numerous and energized.

“We’re going to win this primary,” Miller said Monday in a telephone interview.

Although most Members seeking re-election this year have handily coasted through their primaries, a raft of House and Senate incumbents of both parties have fallen to intraparty challenges.

Meanwhile, some open-seat contests have seen establishment-backed candidates lose to less well-funded underdogs who surged on the strength of tea party support, among them Senate GOP nominees Sharron Angle in Nevada and Rand Paul in Kentucky.

In the Senate, Bob Bennett (R-Utah) and Arlen Specter (D-Pa.) fell to primary challengers, with Blanche Lincoln (D-Ark.) winning her primary only after being forced into a runoff. Bennett probably would have won renomination had he been allowed onto Utah’s June 22 primary ballot, but his defeat at the hands of Republican activists during a state GOP nominating convention provided a window into the anti-establishment sentiment contributing to voter anger.

Public polling in the Murkowski-Miller primary appears to be nonexistent, although the Senator’s campaign indicated in a recent interview that its private surveys show the incumbent comfortably ahead. There is no evidence to suggest otherwise, although Republican sources in Washington say Murkowski has long feared — and thus, prepared for — the possibility of a bruising primary. Murkowski conceded that it could yet get ugly.

“The Tea Party Express is probably the entity, if you will, that has changed the dynamics because they’ve indicated that they plan to put a lot of outside money towards this state,” Murkowski said. “Traditionally, outside groups coming into Alaska, telling us what to do doesn’t set well with Alaskans. We’ll see how that plays out. But if in fact it means that [Miller] is able to gain this level of financial support, it does change the dynamic somewhat.”

National Republican Senatorial Committee Chairman John Cornyn (Texas) predicted Murkowski would prevail, but he said her caution is warranted.

“She’s paying attention and she’s getting prepared, which I think is really important in this political environment,” he said. “You don’t win elections, even re-elections — particularly in this political climate — unless you are prepared and are diligently executing your re-election plan.”

The unique nature of Alaska politics makes the race difficult to handicap.

The Tea Party Express has vowed to fund a substantial media campaign in support of Miller, but it has come under fire for racially tinged comments made by one of its leaders. Palin’s endorsement was a public relations coup for Miller. “It put us on the map, nationally,” he said. But Palin’s disapproval rating in Alaska was 50 percent, according to a May Rasmussen Reports poll.

Miller has interviewed with the Club for Growth. The conservative fundraising powerhouse was impressed and might endorse him over Murkowski, although a spokesman for the group offered no timetable for a decision. However, the club’s strong backing of Alaska’s then-lieutenant governor and now governor, Sean Parnell, in his 2008 GOP primary challenge of scandal-plagued Rep. Don Young failed to produce a victory, leaving the group’s potential effect on the Senate race in doubt.

Alaska primaries are partly open. Independent voters, officially referred to as “undeclared” and “nonpartisan,” are eligible to vote in the Republican and Democratic contests, meaning Murkowski is not going to be judged exclusively by her party’s base. Murkowski said the top issues are jobs and the economy — and the voters’ concern that Washington is the source of problems, not the solution.

Miller’s view is slightly different.

“No. 1 issue is how we perceive the role of the federal government, and everything else follows from that,” he said. “Our perspective is limited Constitutional government. Effectively, Murkowski’s is statist.”