The poll by the Glengariff Group Inc. showed same-sex marriage support has increased to 56.8 percent, up 12.5 percentage points from a year ago, which is largely attributable to changing Republican opinions and independents, The Detroit News reported Tuesday.
The change shows a sharp contrast to voters' approval in 2004 of a constitutional amendment banning gay marriage, the News reported.
The Glengariff poll that year showed only 24 percent of state voters supported lesbian and gay marriages. Fifty-four percent today would repeal the ban and replace it with an amendment allowing same-sex marriages, the poll found.
"I don't think I've ever seen a policy question move as quickly as this one," said Richard Czuba, president of Glengariff, a Chicago firm that since 2004 regularly has polled Michigan voters' positions on gay marriage and civil unions.
The acceptance of same-sex marriage has increased because more residents know gays and lesbians. The increase in acceptance also contradicts the perception that rank-and-file Republicans overwhelmingly are against gay marriage, Czuba said.
The poll found at least 90 percent of the state's voters favor some legal protections for gays and 65 percent favor legal changes permitting civil unions, adoption, inheritance rights, hate crime protections and domestic benefits.
The poll was conducted from May 8-10 and had a margin of error of plus or minus 4 percentage points.
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