Specter, who last year bolted the party to join the Democrats, said on "Fox News Sunday" that Republican objections to several aspects of President Barack Obama's healthcare reforms "are wrong."
"On the Republican side, it is, 'no, no, no,' a party of obstructionism," Specter said.
He cited former Republican U.S. senators including Howard Baker and Bill Frist of Tennessee, and Bob Dole of Kansas, calling them "responsible Republicans ... who say Republicans ought to cooperate."
"Well, they're not cooperating," Specter said.
Specter said a proposed public option to provide a government-run alternative to private health plans is "gaining momentum" despite opposition from Republicans.
"We had a very forceful speech by President Obama yesterday on his Saturday talk show emphasizing the importance of the robust public option to hold down the profits and bonuses, and I'm not going to step back a bit," he said.