Updated

He says he "probably won't do it. But he notes that he's "given it some thought."

Last week, Sen. Lisa Murkowski (R-AK) launched a drastic, last-ditch, write-in effort to try to retain her Senate seat. In August, attorney Joe Miller unexpectedly edged Murkowski to secure the GOP's Senate nomination.

Now a week after losing to tea-party endorsed Christine O'Donnell, Rep. Mike Castle (R-DE) isn't ruling out following in Murkowski's footsteps. O'Donnell upset Castle for Delaware's GOP Senate nomination in the biggest shocker of the 2010 political cycle.

Still, even though Castle didn't hermetically seal the door against a write-in bid, he downplayed the chances that he'd pursue it.

"I'm not exactly approaching this with bated breath," Castle said. "A write-in is logistically difficult."

He added that even though "a lot of people" suggested he mount a write-in campaign, Castle said didn't "want to interfere with Republican chances."

Still, Castle said the abrupt loss left him "hurt and stung."