Since early last year, Planned Parenthood has been under siege. Republicans in the House attempted to end federal funding for the family planning group; legislators around the country cut funds. Abortion restrictions increased. In the Republican presidential primaries, Mitt Romney promised to defund the group.

But in the face of increased opposition, Planned Parenthood found newly intense supporters. And the organization succeeded in widening the debate to include not just abortion but cancer screenings and contraceptives. In last week’s election, results and exit polls suggest, the group won.

In the Sunlight Foundation‘s rundown of outside groups and their success in last week’s election, two groups stand out as getting a near perfect “return on investment” — Planned Parenthood Votes and Planned Parenthood Action Fund, the super PAC and nonprofit arms of the family planning organization.

Women Vote!, the super PAC arm of EMILY’s List, had a solid 80 percent return on investment, meaning 80 percent of the money they spent went to winning candidates or against losing candidates. The group backs only pro-abortion rights Democratic women.

Combined, the two Planned Parenthood advocacy groups say they spent $15 million on ads, phone calls, events, mail and door-to-door canvassing. In 2008, their campaign spending was about $4 million total.

In large part, Planned Parenthood’s success is due to President Obama’s victory. Most of the groups’ money went towards boosting Obama or attacking Romney. Eighty-seven percent of funds spent by Planned Parenthood Action Fund and 80 percent of spending by Planned Parenthood Votes went toward the presidential race, according to the Sunlight Foundation tallies.

But the group also won six out of seven Senate races, three governor’s races and five out of 10 House races.