"I don't believe that Judge Gorsuch, his judicial approach, would ensure fairness for workers and families in Pennsylvania ... and I will not support his nomination," Casey told reporters during a conference call.

Casey, who is up for reelection in 2018 in a state President Trump won, added that he has "serious concerns about Judge Gorsuch's ridged and restricted judicial philosophy."

ADVERTISEMENT

Casey pointed to the "frozen trucker" case, in which a truck driver was fired for leaving his broken-down truck in sub-freezing weather, as one example that concerned him.

"Judge Gorsuch’s opinion in this case and many others show how his judicial philosophy produces rulings disconnected from the lived experience of those they impact," Casey added in a separate statement.

Casey's decision comes after Gorsuch wrapped up his testimony before the Judiciary Committee on Wednesday, with a committee and full Senate vote expected early next month.

Republicans are expected to need 60 votes to get Gorsuch through the Senate, which would necessitate the support of eight Democratic senators.

Both sides are focusing on the 10 Democrats, including Casey, who are up for reelection in 2018 in states carried by Trump.

The National Republican Senatorial Committee immediately pounced on Casey's decision, arguing he was putting the progressive wing of his party above his base.

“By opposing Judge Neil Gorsuch, Bob Casey is aligning himself with the far left instead of honoring the will of Pennsylvania voters. Pennsylvanians will remember Casey’s betrayal when they head to the polls in 2018,” said NRSC spokesman Bob Salera.