Republican Rep. Michael N. Castle of Delaware, the state’s nine-term at-large congressman, announced Tuesday that he would run for Vice President Joseph R. Biden Jr.’s old Senate seat, instantly shifting the race from a safe Democratic seat to a tossup in 2010.
Mr. Castle, 70, a former two-term governor and the state’s longest-serving House member, could face Mr. Biden’s son, state Attorney General Beau Biden, who is weighing his candidacy but has not yet revealed his political plans. The younger Mr. Biden recently returned from a 10-month tour of duty in Iraq as a captain in the Delaware National Guard.
Despite the state’s Democratic leanings, Mr. Castle has won his statewide races with vote-percentage totals in the high 60s or low 70s, and his long-awaited announcement had election forecasters rethinking the race.
“We’re moving the Delaware Senate seat from ‘currently safe for Democrats’ to ‘lean takeover for the GOP,’ ” election analyst Stuart Rothenberg said Tuesday in his Rothenberg Political Report. “However, even if Beau Biden takes a pass on the contest, the combination of the state’s Democratic bent and Castle’s popularity strongly suggest a very competitive contest.”
Mr. Biden’s seat is now held by his longtime aide and fellow Democrat Ted Kaufman, who has said he would not be a candidate next year.
Jennifer Duffy, senior analyst at the Cook Political Report, said Mr. Castle’s decision makes Delaware the “fourth Democratic-held seat that is too close to call and further [levels] the Senate playing field for national Republicans.”
Mr. Castle, a leader of the Republican Party’s liberal-to-centrist bloc on Capitol Hill, said he had been seriously weighing a run for the seat as soon as it became clear that Mr. Biden would be the next vice president. Mr. Castle suffered a minor stroke in 2006 but recovered quickly.
“We need the strongest and most experienced leadership we can find in this country today,” Mr. Castle said at a news conference near the Wilmington train station.
A poll by Rasmussen Reports in September of 500 likely voters showed Mr. Castle leading Mr. Biden by 47 percent to 42 percent, with both men receiving favorable ratings of more than 60 percent. The poll had a margin of error of 4.5 percentage points.
Sen. John Cornyn of Texas, chairman of the National Republican Senatorial Committee, the party’s Senate campaign arm, said Mr. Castle’s move “instantly transforms Delaware into one of the most competitive Senate races in the country in 2010.”
But the Democratic Senatorial Campaign Committee (DSCC), in a broadside attack on Mr. Castle’s voting record, said Tuesday that “Democrats fully intend to hold onto the vice president’s seat.”
Mr. Castle “built up a record of supporting George Bush’s economic policies, including tax cuts for the superwealthy, that drove Delaware’s economy into a ditch - and now [he] won’t support any of the Obama-Biden plans to fix it,” said Eric Schultz, DSCC communications director.