"But for Catholics in favor of prenatal justice, and of government defending these children from terrible violence, we must say that Harris is a deeply flawed candidate. Unreserved praise of her VP candidacy is, in effect, yet another example of erasure of the prenatal child," Camosy said.
Democrats for Life of America also criticized Harris's selection, saying in a statement that she "does not provide pro-life Democrats with any assurances and will, in fact, further alienate 21 million Democratic voters who have been left out of the party for quite some time."
Harris' position on abortion is "far out of line with the majority of Democrats and Americans on this sensitive issue," the organization said, and encouraged Biden and Harris to reach out to pro-life Democrats and adjust the party's platform stances on abortion.
Michael Sean Winters, a writer for the National Catholic Reporter and the author of "Left At the Altar: How Democrats Lost The Catholics And How Catholics Can Save The Democrats," also expressed his reservations about Harris.
"[Massachusetts Sen. Elizabeth] Warren was the person I wanted Biden to choose," said Winters on Wednesday.
"After the racial tensions the nation experienced this summer, putting a Black woman on the ticket is to be commended," Winters said, but called the selection of Harris a "setback for progressives."