The six-term incumbent, who hasn't faced a primary in decades, was forced into one on Saturday when he failed to get 60% of the vote at the state convention.

Washington Post:

Utah Sen. Orrin Hatch will face off against conservative former state Sen. Dan Liljenquist in a June primary after the six-term incumbent failed to win 60 percent of the vote at the state Republican convention on Saturday.

Hatch took 57 percent on the first ballot and then 59 percent on a second ballot, one on one fight against Liljenquist. Hatch needed to win 60 percent of the vote to avoid a June 26 primary.

Hatch forces had hoped to win the nomination outright on Saturday. He came up short on that goal. But, Hatch did avoid the fate of Sen. Bob Bennett (R), who two years ago lost his bid for reelection when he finished third at the state party convention amid deep discontent directed at him from conservatives.

Bennett's defeat served as a wake-up call for Hatch who spent the intervening two years relentlessly courting Utah conservatives in hopes of avoiding his one-time colleague's fate. (Here's a good summary of how Hatch re-made himself.)

Hatch also benefited from some measure of good luck when Rep. Jason Chaffetz (R), who was considered a sure thing to take on Hatch, decided against a bid in August 2011.

If Hatch had suffered the same fate as Bennett, it would hardly have mattered. Utah is one of the reddest states in the nation and given that Mitt Romney will be at the top of the ticket in November, the chances of a Democrat winning the seat are close to zero.

Still, Hatch's situation is instructive. Just because you're an incumbent doesn't mean you're safe from those in your own party who think you've grown fat and comfortable in Washington.