Republican Rep. Shelley Moore Capito will run for Senate in West Virginia

Rep. Shelley Moore Capito (R) Republicans have just landed their biggest fish in West Virginia, where 2nd District Rep. Shelley Moore Capito has just announced a challenge to Sen. Jay Rockefeller, one of the most vulnerable Democratic incumbents up for reelection in 2014, thanks to his state's sharp movement toward the GOP in recent years. The 75-year-old Rockefeller has yet to announce whether he will, in fact, seek a sixth term in the Senate, and a surprisingly anti-coal speech he delivered earlier this year hinted that he might be ready to retire. (Coal is king in the Mountain State and not easily crossed.)

Capito, the daughter of former Gov. Arch Moore, has generally cultivated a profile which has placed her in the left-most quadrant of the congressional GOP, and she's not the type of Republican pol who's likely to embarrass herself or her party. It's easy to imagine she's making such an early announcement in order to push Rockefeller into retirement, but I could also believe she's trying to ward off a tea party-fueled assault from the right in her own primary. Indeed, the Club for Growth is already out with a statement banging Capito, accusing her of having "a long record of support of bailouts, pork, and bigger government."

(And in 2011, conservative businessman Bill Maloney upset former SoS Betty Ireland, the establishment pick, for the GOP nod in the special gubernatorial election. Maloney's better-than-expected performance both in that race and his subsequent rematch attempt this year might make him interested in another bid for office.)

But where does this leave Rockefeller? An August poll from R.L. Repass & Partners actually found him trailing Capito 48-44 in what was at the time a hypothetical matchup. But Repass, which used an odd combination of live and online respondents, didn't perform particularly well this cycle'the same poll, for instance, had Democrat Gov. Earl Ray Tomblin up 21 points in a race he barely won by five. That suggests the survey may have been too pro-Democrat, but on the flipside, Repass was looking at likely 2012 voters. In 2014, Obama won't be at the top of the ticket, so anti-POTUS sentiment will provide less fuel for Republicans.

Rockefeller and the DSCC are obviously conducting their own polling (which we'll likely never see), and that, not anything from Repass, will inform his decision. His age, his health, and his desire to fight a bruising campaign will also presumably play a role. But while on paper Rocky, as the incumbent, has to be considered the Democrats' best hope for holding this seat, I'm also concerned that his remarks about coal could be used to make him radioactive through a harsh and sustained negative campaign. So it's possible that a replacement candidate might, in the end, fare better. Who could that be?

Despite West Virginia's hard-right turn of late, there are still tons of Democratic elected officials in the state, many of whom might be interested in moving up. At the top of the list is probably ex-Sen. Carte Goodwin, who, as an appointee, briefly served out the final months of the late Robert Byrd's term in 2010. Other possibilities include WV-03 Rep. Nick Rahall (though he barely hung on this year with under 54 percent), state House Speaker Rick Thompson, and perhaps even ex-Gov. Bob Wise. (I'd guess Tomblin, having run in two elections for governor in two straight years, probably isn't interested.) Undoubtedly, if Rockefeller steps down (or dithers), many more names will emerge.

Capito's move also makes WV-02 the first official House open seat of the 2014 cycle. While she was the first Republican to win a congressional race in West Virginia since 1983 when she was first elected in 2000, the 2nd District now, oddly, appears to be the most Democrat-friendly of the state's three seats, at least judging by 2012 presidential returns. But at 60 percent Romney, it's certainly not welcome turf, though a local pol with the right profile could make a serious go at flipping this seat. As always, we'll be following all future developments, both at the Senate and House levels, very closely.