44th-annual March for Life in Washington, D.C.

Abortion-rights opponents gather at the Washington Monument to hear Vice President Mike Pence speak at the March for Life rally on Jan. 27, 2017, in Washington.

Pro-life activists gather at the Washington Monument to hear Vice President Mike Pence speak at the March for Life rally on Jan. 27, 2017, in Washington.

Hundreds of thousands of jubilant pro-life activists are in Washington, D.C., for Friday's 44th-annual March for Life, the world’s largest annual pro-life demonstration, buoyed by the prospect of gains under President Trump.

The march is held each year in Washington to mark the anniversary of the 1973 Supreme Court decision legalizing abortion-on-demand.

"We are just delighted so far with what we have seen, in less than a week, from the Trump administration," Jeanne Mancini, president of the March for Life, told LifeSiteNews.

"We saw the Mexico City Policy reinstated. They have mentioned the March for Life in press briefings and in interviews all week long. We have never seen anything like this in our entire life,” she said.

One of Trump's first acts as president was to reinstate the Mexico City Policy, which cuts off U.S. aid to international health groups that promote or provide abortions. He has also vowed to appoint only “pro-life” justices to the Supreme Court and has floated the idea of defunding Planned Parenthood.

What do YOU think? Sound off on the 2017 March for Life in today's WND poll.

"In one week alone, our nation has taken meaningful steps to protect the unborn," said Sen. Orrin Hatch, R-Utah, in a statement. "As one of his first executive orders, President Trump rescinded an Obama-era policy that forced American taxpayers to fund abortions overseas. The House then voted to make permanent the Hyde Amendment, which further protects the conscience of pro-life Americans by prohibiting the use of taxpayer money for abortion."

Sen. Ted Cruz tweeted video of the march which shows the massive crowd and marchers spilling onto the sidewalks and into yards.

Trump expressed his support for the march via Twitter.

“The #MarchForLife is so important,” the president said. “To all of you marching --- you have my full support!”

Trump predicted Thursday the anti-abortion march would draw between 300,000 and 600,000 people.

“You know, the press never gives them the credit that they deserve,” Trump told congressional Republicans gathered in Philadelphia for their annual retreat.“They’ll have 300, 400, 500, 600 thousand people. You won’t even read about it. When other people show up, you read big-time about it. Right? So, it’s not fair, but nothing's fair about the media.”

Trump also brought up the pro-life march when ABC News anchor David Muir asked if Trump was able to hear the crowds from last week's Women's March from inside the White House.

"No, I couldn't hear them. The crowds were large, but you will have a large crowd on Friday, too, which is mostly pro-life people," Trump said. "You're going to have a lot of people coming on Friday. You will have a very large crowd of people. I don't know as large or larger. Some people said it will be larger. Pro-life people and they say the press doesn't cover them."

In an exclusive interview with WNDTV, Troy Newman, president of Operation Rescue, expressed great optimism over the large number of young people participating in the march and the support from Vice President Pence and President Trump.

"This is historic," Newman said. "We're going to overturn Roe v. Wade. ... We've moved the ball so far down the field that we're literally inside the 10-yard line and we need to push it over into the goal. If we don't do it now, we won't have another chance for a decade.

Vice President Mike Pence and Kellyanne Conway, Trump's senior counselor, are among the prominent voices at the pro-life rally.

"Next week, President Donald Trump will announce a Supreme Court nominee who will uphold the God-given liberties enshrined in our Constitution in the tradition of the late and great Justice Antonin Scalia," said Pence at the March for Life. "We will not rest until we restore a culture of life in America for ourselves and our posterity."

Pence is the highest-ranking White House official to speak at the march in its 44-year history. Presidents Ronald Reagan and George W. Bush spoke to marchers via remote audio hookup.

“Our theme this year is the 'Power of One,' highlighting how every individual has the ability to make a difference in the cause of life," said Mancini. "As a former member of Congress, governor and now vice president, Mr. Pence has demonstrated throughout his entire career how one person can, indeed, make a difference in the ultimate human right — the right to life.”

Conway also addressed the crowd, saying that anti-abortion forces had been ignored for too long.

"We hear you, we see you, we respect you and we look forward to working with you," Conway said.

In a recent interview with the Washington Post, Conway said she worries that the country is "becoming too inured and inoculated against how precious life really is."

"But I'm also a very nonjudgmental person. I understand why women are pro-choice. I understand why women get abortions," said Conway.

Read the tested and proven strategies to defeat the abortion cartel, in "Abortion Free: Your Manual for Building a Pro-Life America One Community at a Time."

Pence described Trump as “pro-life” in his remarks at the GOP retreat.

Pence said he "couldn’t be more proud" of the president's order barring the use of federal funds for abortions overseas.

Pence has been a major presence at the March for Life for many years and is considered a champion of the pro-life movement, signing what some consider the strictest laws on abortion in the country as governor of Indiana.

In 2003, he told marchers “abortion is in steep decline in America today … less morally acceptable than any time since 1973.” In 2010, a year into President Obama’s first-term, he decried “a pro-abortion majority in Congress” and “the most pro-abortion president in American history.”

“Ending an unborn human life is morally wrong and it’s also morally wrong to take the taxpayer dollars of millions of pro-life Americans and use it to subsidize abortion at home or abroad,” Pence said at the rally that year.

Behind him stood women holding black signs that said “I Regret My Abortion.”

“Abortion is not health care,” Pence thundered. "Abortion funding has no place in health care legislation now or ever. Abortion organizations overseas have no right to American foreign aid. And the time has come to deny any and all federal funding to Planned Parenthood of America.”

When does life begin? The film "Come What May" presents arguments that one day could be used to overturn the 1973 Roe v. Wade decision. Watch an excerpt here:

Sen. Joni Ernst, R-Iowa, and Reps. Mia Love, R-Utah, and Chris Smith, R-N.J., are among the pro-life lawmakers who will also attend the event.

Watch Rep. Mia Love address the crowd:

Archbishop of New York Cardinal Timothy Dolan, Baltimore Ravens tight end Benjamin Watson, former Planned Parenthood director Abby Johnson, Mexican Telenovela star Karyme Lozano, author and radio host Eric Metaxas and Bishop Vincent Matthews of the Church of God in Christ, who advocates for adoption in the African-American community, will also participate.

“Each of our speakers exemplifies this year’s theme, ‘the power of one,’ in a beautiful way,” noted Mancini. “Their words are sure to motivate the marchers, as well as the millions of pro-life Americans who will be watching, who dedicate themselves to restoring a culture of life in the United States.”

The event begins at 11:45 a.m., with speakers taking the stage at noon and the march beginning at 1 p.m.

Marchers will follow a route up Constitution Avenue to the Supreme Court and the Capitol Building.

Watch more live coverage of the March for Life here: