Tea Party's Next Target: Mike Castle in Delaware

WASHINGTON, Sept. 7, 2010— -- Republican Rep. Mike Castle of Delaware appears well positioned to win next Tuesday's GOP Senate primary and run a competitive campaign for the seat Vice President Joe Biden occupied for 36 years.

He has millions of dollars in his campaign coffers, support from the Republican establishment and a tidal wave of national public opinion swinging in his favor. Recent statewide polls put him well ahead of his opponent, Christine O'Donnell.

But appearances can be deceiving, especially when the Tea Party Express throws its weight behind a primary challenger, as the case of felled Alaska Sen. Lisa Murkowski showed last month.

O'Donnell, a marketing consultant who ran unsuccessfully against Biden in 2008, is vowing to give Castle, a former governor and nine-term congressman, a run for his money, making the race the next big test for establishment Republicans who are trying to keep their jobs.

The Tea Party Express has spent $250,000 campaigning for O'Donnell so far, airing its first ad last week that cast O'Donnell as the more conservative candidate and Castle as "one of the most liberal Republicans in Congress."

Castle voted against the Recovery Act and Democrats' health care law, but he supported the 2008 bank bailout, cap-and-trade legislation and Democrats' campaign finance measure known as the Disclose Act. He also voted for the state fiscal aid bill last month.

A Tea Party Express poll of likely Republican voters last week showed O'Donnell and Castle in a dead heat.

But sources familiar with the Castle campaign say the veteran Republican has been prepared for the challenge in the wake of Murkowski's defeat and adopted a strategy that can win.

"I hear that Congressman Castle is not ignoring his opponent and has paid a lot of attention to what has happened this spring and is modeling his primary campaign after John McCain's primary campaign," Senate Minority Leader Mitch McConnell told ABC News' "Top Line" last week. "And I anticipate people [who do that will] have a better result."

With help from state and national Republican groups, the Castle campaign has gone on the offensive, raising allegations that O'Donnell faced home foreclosure, owed back taxes to the IRS and took 12 years to receive her college degree from Fairleigh Dickinson University because she didn't pay her tuition.

A Castle radio ad calls her "a financial disaster."

O'Donnell has largely denied the claims and accused Castle of employing "goons" to play dirty politics.