Hotline On Call

Sen. Jay Rockefeller (D-WV) will become the first incumbent senator to call it quits when he announces his decision to retire later this morning. He's the first -- though maybe not the last -- senator to create an open seat that will be tough for his party to keep.

For 30 years, Rockefeller has held a vise grip on one of West Virginia's two Senate seats. After winning a close election over businessman John Raese in 1984, Rockefeller never received less than 63 percent of the vote.

But West Virginia is changing rapidly. For generations after the Coal Wars of the 1930s, the state was a reliable source of Democratic votes. More recently, Republicans have made inroads with socially conservative Yellow Dog Democrats, a trend that's accelerated along with what Republicans term President Obama's war on coal.

Democrats still hold both Senate seats and the governor's mansion, but Sen. Joe Manchin and Gov. Earl Ray Tomblin won narrow victories in 2010 and 2012, respectively, and Republicans defeated the Democratic attorney general last year. In 2010, Republicans elected two of the state's three members of Congress, their first majority since the Reagan landslide in 1980.

Republicans already had their eye on Rockefeller's Senate seat. Just weeks after Election Day last year, Rep. Shelley Moore Capito, a candidate Republicans have been trying to get into a statewide race for years, said she would finally take the plunge and seek higher office (Conservatives have threatened to challenge Capito in a primary, though national Republicans will give her their full support).

Democrats still control enough statewide offices to give them a few rising stars. Secretary of State Natalie Tennant, who ran unsuccessfully for governor in a special election in 2011, is likely to top any list of potential Democratic candidates. Former Sen. Carte Goodwin, who temporarily served in the Senate after Robert Byrd passed away in 2010, is also likely to get a phone call from top Democrats looking for a candidate.

But holding an increasingly red state won't be a slam dunk for the blue team. And this cycle, the party is likely to face a few more retirees in states that qualify for the swing column. Sens. Tim Johnson (D-SD) and Tom Harkin (D-IA) have not definitively said whether they will seek another term. Incumbents in more solidly blue states like Illinois and Michigan are also on the retirement watch list.

Update: We mistakenly wrote Max Baucus's name instead of Tim Johnson's. Baucus is likely to run for re-election.