Updated: 11:21 a.m.

Rep. Bart Stupak (D-Mich.), who led a key group of anti-abortion-rights House Democrats that helped secure passage of President Barack Obama’s health care overhaul, announced Friday that he will retire from Congress at the end of his ninth term.

In a letter to his constituents, Stupak said he wants to spend more time with his family after 18 years in Congress, and he said he accomplished what he set out to do by passing the health care overhaul.

“As you know, for the last several years, I have considered retiring from Congress — to spend more time with my family, and to consider new chapters in my life,” Stupak wrote in a letter to his constituents. “My service to the people of Michigan has been the greatest honor of my life. But this year, after all that we’ve accomplished, I have decided to begin that new chapter.”

Stupak cited the passage of the health care overhaul as the fulfillment of a campaign promise he made in his first race in 1992 to make health care a right, not a privilege. Stupak, a former state trooper, had refused to accept the Congressional health care plan until all Americans had access to the same level of care and listed a series of benefits he said the bill would bring to his district.

His decision came even though top Democrats called him this week presumably to encourage him to stick around.

Stupak became a lightning rod for the left and the right during the health care debate, after playing center stage for months in a standoff over abortion language, and he faced attacks from both tea party activists and abortion-rights supporters.

Stupak authored a strict anti-abortion amendment that was adopted on the House floor with bipartisan support that would have prohibited women from buying insurance plans covering elective abortions if they received any federal subsidies. Stupak and his group had been threatening to block the Senate health care bill, contending that the abortion language passed in that chamber’s measure did not go far enough. But they were ultimately won over by an executive order reiterating that no federal funding would pay for elective abortions.

Passage of the bill was not assured until Stupak held a 4 p.m. press conference hours before the final House vote to announce his support.

Republicans argued that Stupak’s retirement signaled that fallout from that deal would cost Democrats seats.

“After selling his soul to Nancy Pelosi, it appears that Bart Stupak finally found the courage to tell her ‘no,'” National Republican Congressional Committee spokesman Ken Spain said. “The political fallout over the Democrats’ government takeover of health care has put the political careers of many Democrats in jeopardy thanks in-part to Stupak’s decision to abandon his alleged pro-life principles.”