Pro-life Democrats constitute 22 percent of the party but only 1.6 percent of the House Democratic Caucus, and that number may be set to drop further on Tuesday.

NBC News correspondent Steve Kornacki tweeted statistics from the group Democrats for Life showing the gaps between voters and representatives on abortion, noting pro-life Illinois Rep. Dan Lipinski (D.) is one of only three pro-life Democratic House members. Lipinski is running to retain his seat against pro-choice primary challenger Marie Newman, who has racked up endorsements from such left-wing stars as Sen. Bernie Sanders (I., Vt.).

"3 of 193 (1.6%) of House Dems are now anti-abortion, while according to Pew 22% of Democratic voters are," Kornacki said.

3 of 193 (1.6%) of House Dems are now anti-abortion, while according to Pew 22% of Democratic voters are: pic.twitter.com/I79b68oMyu — Steve Kornacki (@SteveKornacki) March 20, 2018

Kornacki also pointed out how the Democratic Party has shifted toward a unified hard line in favor of abortion. When Democrats last retook the House in 2007, they had 32 representatives who were against abortion, a far cry from the three now in office.

Many Democratic lawmakers had held pro-life views even years after the 1973 Supreme Court case Roe v. Wade granted a constitutional right to abortion in certain cases. If Lipinski is voted out, only 1 percent of House Democrats would be pro-life.

Lipinski has warned Democrats not to expel pro-lifers from the party. He said last week they would hurt themselves politically if they require that representatives hew to pro-choice orthodoxy.

"It would be a disaster," Lipinski said. "We need to make sure that we are a big-tent party."

The primary has received national attention owing to the number of progressive leaders and activists who have put their support behind Newman. In addition to Sanders and other politicians, comedienne Chelsea Handler called on voters to back Newman.

"This is another race on Tuesday in Illinois. Marie is running against a crook with a terrible record," Handler commented, retweeting a tweet from Newman. "Let’s make Tuesday another day we elect candidates that say no to Russia and no to Trump. Be part of the blue wave!!!"

This is another race on Tuesday in Illinois. Marie is running against a crook with a terrible record. Let’s make Tuesday another day we elect candidates that say no to Russia and no to Trump. Be part of the blue wave!!! https://t.co/6vc8XXh6mB — Chelsea Handler (@chelseahandler) March 16, 2018

Lipinski has called for strong sanctions against Russia, so it is unclear what point Handler was making. Lipinski himself, a seven-term Democratic representative, has criticized Democrats for taking on him and other Blue Dog Democrats, and "chas[ing] people out of the party."