Abortion foes, encouraged by GOP control of the House and now also the Senate, are rallying behind a bill they believe will be the first step in a new campaign against the procedure.

Congressional Republicans are fast-tracking legislation that would prohibit abortion 20 weeks after fertilization, with the House likely to bring the Pain-Capable Unborn Child Protection Act up for a vote on Jan. 22 to coincide with the anniversary of the 1973 Roe v. Wade decision. Sen. Lindsey Graham, R-S.C.,​ in the weeks to come ​​​​is expected ​​​introduce a version in the ​​​​​​Senate, where ​Majority Leader Mitch McConnell, R-Ky., ​has promised ​he would bring it to a​ vote.

A similar ​​ban ​after 20 weeks -- reflecting beliefs about when the fetus can feel pain -- was approved in ​the Republican-controlled House ​in 2013 but languished in the Senate under then-Majority Leader Harry Reid, D-Nev. ​​​​​​The bill didn't pass the House ​without controversy, though. In response to calls for a rape-exemption, Rep. Trent Franks, R-Ariz., said​​​​​​​ "the incidence of rape resulting in pregnancy are very low.” Franks, the bill's sponsor, later attempted to walk back the remarks after they were widely reported. T​he latest version of the legislation, introduced by Franks the first day of Congress on Jan. 6, includes exemptions for incidences of rape or incest and to protect the life of the mother. But even some female GOP lawmakers believe those exemptions aren't wide enough, according to a report Friday in Politico, as women seeking the rape exemption would be required to report the assault to police.

Only a small portion -- a little over 1 percent -- of abortions take place 21 weeks or later after gestation (the bill’s ban amounts to 22 weeks into gestation, measured by the time of a woman's last missed period​). Yet passage of the measure -- which faces an almost certain White House veto if it's approved in Congress -- would be a major victory for abortion opponents.

“It is a starting point. There is a direct route to very quickly -- it involves a presidential election -- to pass this legislation,” Marjorie Dannenfelser, president of the anti-abortion advocacy group Susan B. Anthony List, said at a National Press Club event Thursday.

“When that happens, it will be the first time in 40 years that we have drawn a line and said, 'After this point, no more.'”

A majority of Americans -- 60 percent in a November Quinnipiac University poll -- support banning abortion after 20 weeks. With President Barack Obama signaling his opposition, proponents compare the proposal’s path to that of the partial-birth abortion ban, which was signed into law by President George W. Bush after President Bill Clinton vetoed it twice before. They hope to make it an issue in the 2016 presidential campaign.

Furthermore, they believe the debate of the 20-week ban at the national level will encourage more state legislatures to take up the proposal. Lawmakers in South Carolina, Wisconsin and West Virginia have floated similar measures, which in turn will bulwark support for federal legislation.

Even with the relative rarity of abortions after 20 weeks, reproductive rights groups are lining up against the bill.

“This is an unconstitutional ban. This is something that we expect to defeat,” said Planned Parenthood Federation of America president Cecile Richards at a National Press Club conference Wednesday.

“What we’ve seen is that when people understand the situations women are in and see the importance of doctors being able to make decisions in the case of abortion circumstances, voters don’t believe politicians should be making medical decisions for women and their families.”

Opponents of the ban point out that the 20-week mark is around the time that deformities in pregnancies often become known, and Planned Parenthood polling shows support of the prohibition shrinks to 31 percent in cases of fetal abnormalities, which are not exempted by the federal legislation.

Additionally, research has suggested ​that women who seek abortions late in the term are younger and more likely to be unemployed and often face other challenges such as domestic violence, single parenthood, substance abuse or trouble accessing services. Such circumstance are bound to be further complicated by the wave of recent state abortion regulations that have extended waiting periods and forced clinics -- particularly those in rural areas -- to close.

“The bottom line is the way that women are paying the price on both ends of these abortion restrictions,” says Heather Boonstra, director of public policy at the Guttmacher Institute.

The underlying premise of the bill, the contention that fetuses can feel pain at 20 weeks, is also widely disputed. Several studies suggest that festuses do not develop the sensory system to feel pain until closer to 30 weeks into gestation. However, some medical professionals have testified that fetuses are capable of pain at 20 weeks or even earlier.

Thirteen states have sought to enact measures that ban abortion 20 weeks after fertilization or earlier, but some laws that have passed have been met with legal challenges. The Supreme Court has defined protections for abortion up to 24 weeks into the pregnancy, the point of viability. An appeals court is currently weighing decisions by federal judges to strike down laws in North Dakota and Arkansas that ban abortion after six weeks and 12 weeks, respectively, and last year the Supreme Court let stand a lower court's decision declaring unconstitutional an Arizona law that banned abortions 18 weeks after fertilization.

But supporters of the 20-week ban argue that the Supreme Court's 2007 Gonzales v. Carhart decision, which upheld the federal partial-birth abortion ban, shifted more power to the government to consider legislation in the interest of protecting the fetus. They also say that state bans crafted specifically around the question of whether a fetus is capable of feeling pain have fared much better under judicial review -- only two of the 10 state laws where that is the main justification currently face legal challenges, according to Douglas Johnson, legislative director for the National Right to Life Committee.​

"We think they read Gonzales like we do, and they don't want this type of legislation to go to the Supreme Court," he says.​

Holding the 20-week ban legislation up to courts to see if it succeeds is also part of the long game of some activists seeking to see abortion outlawed once and for all.