SALT LAKE CITY — Utah passed sweeping changes to a voter-approved Medicaid expansion Monday, cutting the number of people covered nearly in half and adding work requirements that the Trump administration is expected to approve. Republican Gov. Gary Herbert signed the plan hours after it cleared a final vote in the Republican-led Legislature, calling it both “humane and sustainable.” It’s drawn vocal protest from advocates who say the changes go further than any of the four other conservative-leaning states where voters expanded Medicaid after state lawmakers refused. “This is a dark day for democracy in Utah,” said Andrew Roberts, a spokesman for the group Utah Decides.