CHICAGO — Expecting significant budget shortfalls this year and in the years ahead, Bruce Rauner, Illinois’s new Republican governor, on Wednesday proposed more than $6 billion in cuts in state spending on universities, health care, local governments and other areas and called for sharply reducing pension benefits for state workers.

Though many of his cuts are likely to face opposition in the Democratic-led legislature, his proposal for solving the state’s crippling pension crisis may be the most contentious. He called for most public workers covered by the state’s pension system to be moved in the coming months into a plan with lower benefits — a move that he said would save the state $2.2 billion in the coming budget year and more than $100 billion over the next three decades.

“This budget is honest with the people of Illinois, and it presents an honest path forward,” Mr. Rauner said as he laid out what he deemed a “turnaround budget” before lawmakers in Springfield, the state capital. “Like a family, we must come together to address the reality we face. Families know that every member can’t get everything they want.”

The fate of Mr. Rauner’s $31.5 billion spending plan, however, is uncertain, particularly given that Democrats hold veto-proof majorities in both chambers of the legislature. Democrats said it would harm middle-class families and the poor, while asking little more from wealthy residents. The proposed budget calls for no tax increases or new taxes.