Bob Bennett's Senate career may be over sooner than expected, according to Rep. Jason Chaffetz (R-Utah), who has experience with embattled incumbents.

The Utah Republican must get at least 60 percent of the delegate vote at the May 8 state Republican Party convention to clinch the Senate nomination without a primary. He needs to break 40 percent to ensure he's in that primary.

"The conventional wisdom was that Bennett was at least going to get out of convention, but I think that's in serious doubt," Chaffetz told the Salt Lake Tribune Wednesday. "Go try to find a Bennett delegate. They're pretty hard to come by."

Utah's primary is June 22 -- Bennett is facing seven Republican challengers.

Chaffetz defeated then-incumbent Rep. Chris Cannon in the 2008 GOP primary. "A lot of people were very skeptical about how realistic knocking off an incumbent can be," he noted.