Sen. Arlen Specter said he anticipates facing Democratic challengers in the Pennsylvania Senate primary, disputing the notion that party leaders would clear the field for him following his defection from the GOP. 

Specter told NBC'S "Meet the Press" Sunday that he was offered no incentives from Democrats to switch parties. And he said despite public support voiced for his decision by President Obama, Pennsylvania Gov. Ed Rendell and Senate Majority Leader Harry Reid, those leaders have not seen to it that he'll have a clear path to the 2010 nomination. 

"I didn't ask them to clear the field. The reality is you can't tell other people what to do," Specter said. "I'm prepared to run in a contested primary." 

He noted there are two candidates in the field and "others on the sidelines" waiting to throw their names in the ring. 

Rep. Joe Sestak, R-Pa., is among those considering a bid against Specter in the primary. "I have not made up my mind on it," he told FOXNews.com after Specter announced his switch. 

Another potential challenger to Specter for the Democratic nomination is Joe Torsella, a former Rendell aide who headed the National Constitution Center and is now chairman of the Pennsylvania Board of Education. In a written statement Tuesday, Torsella reiterated his intention to run. 

But Rendell said in a recent TV interview, conducted before Specter's party switch, that Specter would be "unopposed" for the Democratic nomination if he went down that road. 

Challenged or not, Specter has a decided advantage. Obama is prepared to campaign and raise money for Specter if asked. Specter also has $6.7 million in the bank, far more than any of his potential competitors. 

Specter said Sunday his principal concern in the upcoming race is, "I don't want to run against a stacked deck like I would have had to against the Republican primary electorate." 

He repeated his claim that he switched parties for two big reasons: He probably would not have won the GOP primary and he no longer felt ideologically connected to the GOP as a whole. 

"The Republican Party has gone far to the right," he said. 

Before Specter switched, polls showed former Rep. Pat Toomey leading Specter in the GOP primary. Toomey is seen as the favorite to win the GOP primary now that Specter is out of it, but there are now reports that Tom Ridge -- former Pennsylvania governor and homeland security secretary -- wants a go at it. 

Asked about the speculation Sunday, Specter said: "I think former Governor Ridge is a very able fella and I have a lot of respect for him." 

Despite the built-in advantage Democratic candidates enjoy in Democrat-heavy Pennsylvania, Republicans have voiced determination in putting up a formidable candidate against Specter in the general election. 

"I know as Republicans that we have some great candidates that we're recruiting out there, and we want to make sure that Arlen Specter is no longer in the United States Senate after the next election," Sen. John Ensign, R-Nev., told "FOX News Sunday." "We're going to work very hard to make sure that happens."