The White House is silent as House Republicans prepare to pass a novel law curbing second trimester abortions, despite furious opposition from President Barack Obama’s allies in the abortion-advocacy groups.

Representatives will vote July 31 for or against the bill, which would limit abortions in the District of Columbia of unborn humans who able to sense pain, which occurs at roughly 20 weeks.

The law would not cover abortions outside the district, but would boost the national campaign to pass similar laws in states. So far, legislators in seven states have passed laws curbing abortion after the baby’s brain develops enough to register pain.

“The White House has not said a peep about [the pending bill, but] it would seem appropriate that people know what its position is,” said Doug Johnson, director of the National Right to Life Committee.

Johnson said he’s confident that Obama opposes the bill’s curbs on abortions.

Josh Earnest, the White House’s deputy press secretary, did not respond to questions from The Daily Caller.

Obama has worked hard to keep support from pro-choice groups, partly because they help spur Democratic support and turnout among single women and female post-graduates.

But the bill is popular and the new focus on infant’s pain can further weaken support for unrestricted abortion access, say proponents.

A July poll of 1,000 adults showed that 58 percent of adults would be more likely to vote for legislators who support the legislation. Only 27 percent of the adults would be less likely to back supportive legislators, according to the poll, conducted by the polling company, inc.

Obama’s silence may anger abortion-choice advocates, but those advocates will likely support Obama in his campaign against Mitt Romney.

The pending bill is called “The Pain-Capable Unborn Child Protection Act.” It has enough Republican and Democratic sponsors — roughly 223 — to pass once it comes up for a vote July 31. The bill is being pushed by Arizona Republican Rep. Trent Franks.

The bill would not limit abortions needed to save a woman’s life or prevent irreversible health damage.

The new pain-focused law is the next step after the successful campaign to curb partial-birth abortions, said Johnson.

Johnson and his allies successfully waged a multi-year campaign to limit partial-birth abortions, in which the infant is partly pulled from the women before being killed. The campaign helped build public support for pro-life policies, say pro-life advocates.

In 2007 the Supreme Court upheld a law curbing those partilal-birth abortions, marking an important step away from its previous policy barring significant legal curbs on early or late abortions.

Senate Democrats will stop the bill this year.

But abortion-choice activists fear the new pain-focused approach, just as they opposed the campaign against partial-birth abortions, Johnson said.

Abortion-choice advocates strongly oppose the measure.

“If there were an Olympic event for the most out-of-touch and heartless policy, anti-choice politicians in the House, sadly, would have no competition for the gold medal,” said a July 27 statement from Nancy Keenan, president of NARAL Pro-Choice America.

“Radicals” are pushing the bill, which would “ban abortion care at 20 weeks in Washington, D.C., imposing penalties and/or jail time on doctors who provide this necessary health care, even those stepping in to preserve a woman’s health,” said a May statement from the National Organization for Women.

D.C.’s lone non-voting delegate in Congress also opposes the bill.

“Women nationwide know that the D.C. label on the bill is cover for the far-right campaign that began in the states… We will defeat this full-throttle attack on our women and on our city in the courts, if necessary,” said Del. Eleanor Holmes-Norton. Scott McCrary, a spokesman for Holmes-Norton, declined to respond to questions from The Daily Caller.

“If we can achieve a big majority on this groundbreaking initial vote, it will lay the foundation to achieve legal protection for pain-capable unborn babies in the not-distant future,” Johnson said in a statement.

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