Yet "he really has delivered for Catholic voters" on the life issue and on religious freedom, Mercer said.
Pro-life advocates have also been making phone calls and house visits in support of Trump. Earlier in 2016, the Susan B. Anthony List and Women Speak Out PAC announced a $52 million campaign to target swing state voters and highlight what they see as Trump's pro-life credentials and Biden's abortion support.
On Monday, the groups said they had reached more than eight million voters and visited 2.5 million homes in swing states.
Mallory Quigley, national spokeswoman for the independent expenditure campaign, told CNA that the response has been encouraging-particularly from "persuadable" voters or pro-lifers who are "inconsistent" voters.
"Life is definitely a winning issue. We've known this. We've seen it. We've seen it change votes in the last three election cycles," she said.
For many persuadable voters, their support of President Trump's re-election in 2020 comes down to policies and not the personality of the candidate, she said.
"A lot of people who did not vote for Trump in 2016 that are going to vote for him this time," she said, because he "has followed through on every commitment that he has made to the pro-life movement that is within his power to do."
"Even if they want to support a pro-abortion Democratic candidate because of their support for other issues" such as immigration or climate change, she said, "once they hear about how far Democrats will go on abortion" then "that knowledge is powerful enough for them to then change their vote."
But despite the turn out efforts for the president among pro-life groups, Hayes said many Pennsylvania Catholics now regret their support of Trump in 2016. He blamed the Democrats' loss in 2016 in part on a lack of focus on religious voters by the national campaign.
"I think it's fair to say many Catholics voted for President Trump because they were not fans of Hillary Clinton, and the Clinton campaign did not do an effective or a very overt outreach to faith communities, particularly Catholics.," Hayes told CNA. "And that turned a lot of Catholics off."
However, many of the same households that supported Trump out of a desire for "change" now say they "didn't realize it was going to be this bad," he said.
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Biden's support for abortion has been a focal point of Catholic critics of his campaign.
"The message we've been bringing to people that being pro-life is really about multiple issues and abortion is one of them, but it's not the only issue that Catholic voters need to keep in mind," Hayes said.
Biden has promised to codify Roe v. Wade, cover abortions on "public option" health care plans, fund elective abortions through Medicaid reimbursements, and publicly fund abortion providers such as Planned Parenthood.
When Biden reversed his support of the Hyde Amendment-a policy that limits taxpayer funding of abortions-that came amid serious pressure from the left during the primaries, Hayes said.
"I really wonder after he's elected if he's going to go there or not. And I think there are Catholics who are Democrats who are going to appeal to him to not repeal the Hyde Amendment. We'll see what happens," he said.
House Speaker Nancy Pelosi has already promised not to include the policy with spending bills next year, setting up a possible fight in Congress over the issue.