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WASHINGTON , D.C. - Numbing cold didn't stop thousands of anti-abortion activists from descending on the nation's capital today for their annual "March for Life."

The demonstration falls each year on the anniversary of the Supreme Court's 1973 decision to uphold a legal right to abortion in Roe v. Wade. But with unusually frigid temperatures hovering between 14 and 20 degrees Fahrenheit today, picketing through D.C.'s slushy streets from the National Mall to the judiciary was more like a trudge. Hoisted signs with slogans like "Defend Life" and "Equal Rights 4 Unborn Women" were held aloft by gloves concealing hand warmers.

Speaking with the snowy U.S. Capitol behind her, March for Life president Jeanne Monahan spoke on this year's theme of adoption as an alternative to abortion.

"When a woman is facing an unexpected pregnancy and she makes the choice to be a birthmother, she is being a heroic mother in the truest sense because she is making the ultimate sacrifice out of love for her child. In doing so she also helps another family embrace life," she said.

House Majority Leader Eric Cantor, R-Va., told demonstrators, "In the not-too-distant future our movement will be victorious" and "secure a culture of life."

"I believe this for one very simple reason," he said. "The truth is, there is an inalienable right to life, and this right extends to the unborn. This is not a political truth subject to the whims of man. It is a moral truth and was written, as one famous Virginian noted, by our creator."

The lawmaker trumped recently passed bills in his GOP-controlled chamber to hinder abortion, but yielded it would be "a much tougher task" to pass through the Democratic majority in the Senate and the White House. Such legislation is tabled in limbo until the balance of power changes.

"But I can make you this promise," Cantor continued. "The people's House will stand for life. And we will do everything in our power to make sure that our values and the sanctity of life are reflected in the law of the land."

He shared the podium with fellow members Rep. Chris Smith, R-NJ., and Rep. Vicky Hartzler, R-Mo. Focus on the Family founder James Dobson and a half dozen other activists also spoke on the National Mall grounds.

Washington typically experiences fairly mild winters and today's cold did hinder some events for the activists, however. Democratic Rep. Dan Lipinski was scheduled to speak but national flight delays from the recent winter storm reportedly stranded him on the tarmac in his home state of Illinois. On Tuesday a 5K marathon named for the march's founder, Nellie Gray, was also cancelled due to the chill.

Pope Francis, home at the Vatican, expressed support for the demonstrations via Twitter.

"I join the March for Life in Washington with my prayers," it read. "May God help us respect all life, especially the most vulnerable."

Demonstrators in support of abortion rights held similar gatherings throughout the city albeit with far fewer numbers. In one outing, a few dozen "Pro Choice" activists organized outside the Supreme Court, but were dwarfed by the March For Life procession when it arrived in early afternoon.

A July ABC News/Washington Post poll found 55 percent of Americans support a right to abortion in most or all cases; 41 percent opposed. The numbers have remained relatively static over the last 10 years.

As the Republican National Committee begins its annual winter meeting in Washington's Renaissance Hotel this week, members of the GOP are scheduled to meet with abortion foes and are expected to discuss ways to hinder abortions without overturning Roe v. Wade outright. The Supreme Court decision has already survived four decades of challenges from opponents.

Requiring the notification of a spouse before a woman undergoes the procedure and mandatory waiting periods for would-be patients are examples of measures that could be pursued at the state and federal level. Such methods have already taken off in some state legislatures as activists seek ways around Congress to chip away at the practice - more restrictions were placed on abortion at the state level in the last two years than in the previous decade. In 2013 alone 53 were passed, according to the Associated Press.