"As a D.A., you're kind of on God's side," said Marcel Groen, the Democratic Party chair for Montgomery County. "It's pretty hard to mess that up, and he was pretty popular."

So, the same week in 2003 that he was reelected county district attorney, Castor announced he'd run for attorney general.

A career debacle

The failed campaign never got past the primary level. Though it broke his name statewide, it haunts his career.

Christian Marrone, now the estranged son-in-law of convicted former State Sen. Vincent J. Fumo, worked on fund-raising and other politicking needs for Castor, who coordinated the work by e-mail and meetings in the District Attorney's Office. At Fumo's trial, Castor testified he "probably shouldn't have" used county resources, and County Commissioner Joseph M. Hoeffel III, a Democrat, lambasted Castor for "political abuses" of his office.

"It was a mistake to let [Marrone] become involved" in the campaign, Castor said.

During that campaign, Castor blamed Republican power-broker Bob Asher for having "hijacked" key endorsements for his primary opponent, Tom Corbett. The two had history: law-and-order Castor had helped block Asher, convicted of a corruption felony from 1986, from appointment to the SEPTA board in 2001. It grew into political war when Castor questioned Asher's role in Corbett's campaign.

Now Castor talks of rapprochement.

"There aren't so many people that have my profile that you can throw away any," Castor said. "Maybe this Senate seat will be an opportunity to try to repair that rift."

Asher has little, if any, interest.

"He's not even on the face of the Earth," Asher said. "He's not even part of the Republican plan for the Commonwealth of Pennsylvania."

Limited effectiveness

Castor's broad appeal as a two-term district attorney got him the most votes of any commissioner candidate in 2007. He said he ran to help retain the GOP's hold on county government, but then the second- and third-place finishers, Hoeffel and Republican James R. Matthews, united against him, finding party differences less problematic than Castor.

He has fumed at length during county commissioner meetings. Hoeffel and Matthews frequently pass measures by a 2-1 vote, and Castor has unsuccessfully fought policies on ethics and economic development, several hiring decisions, and the county's 2009 budget.

"There's no partisan way to take out the trash," said Matthews, "and yet we've had all these negative votes and divisiveness."

Observers see little proof of effectiveness.

"He's earning a reputation that he can be difficult to deal with in a legislative setting," Kennedy said. "His career setbacks have not been at the hands of the Democrats. They have been at the hands of people in his own party. That may tell you something."

Castor's hope of escaping to the state Senate lies, for now, entirely in the hands of Republican leaders.

GOP delegates from Montgomery, Bucks, Lehigh and Northampton Counties will soon choose their preferred candidate for a special election this fall.

Castor and State Rep. Bob Mensch (R., Montgomery), who has few enemies, are said to be leading the field.