Sen. Arlen Specter of Pennsylvania said he did not seek and was not given any assurance that he would not face a primary challenge when he decided to leave the Republican Party to join the Democrats.
"I didn't ask that the field be cleared. There was no discussion of that," Specter said on "Fox News Sunday," when asked about a possible Democratic primary challenge by Rep. Joe Sestak (D-Pa.). "Everybody ought to run if he or she wants to run. And I'm ready to take on all comers."
Sestak has said he is seriously considering taking on the incumbent.
Specter, asked whether he could beat Sestak in a primary battle, said, "In a political campaign, there's no such thing as certainty."