The percentage of Indiana residents who oppose a proposed gay marriage ban has increased 4 points since last year.

The constitutional amendment, proposed by Rep. Eric Turner, a Republican, seeks to prohibit the state from recognizing any union other than a heterosexual marriage. It is expected to clear its final legislative hurdle early next year and make its way to the 2014 ballot.

According to a WISH-TV/Ball State Hoosier Survey released Thursday, only 38 percent of respondents support the amendment, while 58 percent oppose it – a 4 percent increase from last year's poll.

Joseph Losco, chairman of Ball State's Department of Political Science, said the poll shows the amendment's chances β€œdepend a lot on voter mobilization next year.”

A large majority (77%) of Democrats oppose the amendment, while Republican opposition is at 40 percent.

Hoosiers are more divided on whether the state should allow gay couples to marry, with 48 in support and 46 percent opposed. Last year's poll found support and opposition split evenly at 45 percent each.