WASHINGTON—Senate Republicans’ plan to extract more savings from Medicaid as part of their revised tax and spending package triggered a backlash within the party, raising concerns that leaders could miss their self-imposed deadline of getting the bill to President Trump’s desk by July 4.

Medicaid provisions in Republicans’ reconciliation megabill would lead to between 8,000 and nearly 25,000 medically preventable deaths, according to new research in the Annals of Internal Medicine.

As Republican senators consider President Donald Trump’s big bill that could slash federal spending and extend tax cuts, a new survey shows most U.S. adults don’t think the government is overspending on the programs the GOP has focused on cutting,