Three days after headlining the Obama campaign's roll-out of GOP supporters, former Sen. Lincoln Chafee (R-R.I.) announced today that he will join the board of directors for NARAL Pro-Choice America this fall.

Chafee, now an independent, said abortion rights provide a stark difference between Barack ObamaBarack ObamaPresident-elect Trump, don’t tamper with the successful Endangered Species Act Be warned, GOP — There are no 'permanent majorities' in American politics National service, not government, will make America great MORE and John McCainJohn McCainThe rise of Carlson, and the fall of Van Susteren Booker to vote against Tillerson Earnest: GOP intellectually dishonest on Manning pardon MORE, blasting the Arizona Republican for not supporting them at a federal level. Chafee endorsed Obama in February.

"I have always said that being pro-choice is a mainstream conservative value," Chafee said. "It is unfortunate that Sen. McCain does not share the view of many mainstream Republicans that privacy and freedom from government interference in personal decisions is a core value."

"This is one of the clearest differences between Sen. Obama and Sen. John McCain--and it is a difference that matters to voters, including pro-choice Independent and Republican women," Chafee said.

McCain yesterday floated the possibility of tapping a pro-abortion-rights running mate in an interview with The Weekly Standard. McCain has said he would like to see Roe v. Wade overturned, giving states authority over abortion rights, and for the U.S. to work toward ending abortion as a practice.