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 Hussein ObamaObama to visit Kenya, South Africa for Obama Foundation in July Overnight Energy: EPA declines to write new rule for toxic spills | Senate blocks move to stop Obama water rule | EPA bought 'tactical' pants and polos Clarifying the power of federal agencies could offer Trump a lasting legacy MORE and John McCainJohn Sidney McCainDon’t disrespect McCain by torpedoing his clean National Defense Authorization Act Meghan McCain rips Trump's 'gross' line about her dad Trump's America fights back 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.