The bad news: He’s only 68 and this would have been an easy hold. As it is, Democrats will take a crack at it in hopes of offsetting losses by vulnerable midwestern Blue Dogs like Nelson, Tester, and McCaskill. In fact, Larry Sabato’s already downgraded the seat from solid Republican to leans Republican.

The good news: Are you ready for Senator Meghan McCain?

Two GOP sources confirm to Fox that 3-term Senator Jon Kyl will announce his retirement at a noon news conference Thursday in Phoenix.

The Arizona lawmaker is the No. 2 Republican in the Senate.

Kyl, 68, served four terms in the House before winning a Senate seat. In 2006, he was named one of the 10 best senators by Time Magazine.

Analysts on both sides are already whispering Giffords’s name as a potential Democratic contender, which assumes a lot about the progress of her rehab but makes perfect sense given the sentiment in her favor. If not her, maybe … Napolitano, who used to be governor? On the GOP side, no worries about Meggie: She’s still a few years too young to be constitutionally eligible. Besides, isn’t there already an obvious frontrunner?

Exit question: Who’ll replace Kyl as number two in the leadership? Take your pick, says Politico — John Cornyn or Lamar Alexander.

Update: The Hill says he has his eye on a Supreme Court appointment or a Cabinet position if a Republican is elected president in 2012. But why does he have to retire now to put himself in position for that?

Update: Flake is coy.