Senate Republican leaders continue to scrounge for votes to pass Donald Trump’s $3.3 trillion tax and spending bill as lingering intraparty fights threaten to upend the legislative centerpiece of the president’s domestic agenda.

Senate Democratic Leader Chuck Schumer of New York said the “hardest choices” for Republicans are still to come. His side plans to bring “amendment after amendment after amendment to the floor, so Republicans can defend their billionaire tax cuts and so they can try to explain their massive cuts to Medicaid to people back home.”

Trump on Saturday lashed out at Tillis, warning that he was making a “BIG MISTAKE” and calling him “a talker and complainer, NOT A DOER!” He celebrated the news of his retirement on Sunday night, but has not yet reacted publicly to the senator’s speech.