WASHINGTON (AP) — Ohio voters rejected a proposal that would have made it more difficult for voters to amend the state constitution, including one measure set for the November ballot that would guarantee abortion rights in the state.

The Associated Press has called Tuesday's race, determining that supporters of the proposal known as Issue 1 fell short in their effort to require future changes to the state constitution to win the support of 60% of voters instead of a straight majority.

Votes cast against the measure, or No votes, received 57% compared to 43% in favor with the count nearly...