A surprising poll has revealed that many Republican voters consider opposition to same-sex marriage a “deal breaker” in their political representatives.

The primary polls, conducted by NBC and Marist College, show that about half of likely GOP caucus and primary voters in Iowa, New Hampshire and South Carolina said they find opposition to gay marriage either “mostly” or “totally” unacceptable in a candidate.

Fifty-two percent of likely Republican primary voters in New Hampshire and South Carolina said opposing gay marriage is either mostly or totally unacceptable, while 47 percent of likely Iowa caucus voters agree, reports the Washington Post.

Also likely to alienate voters, claimed the poll, were favouring immigration reform, belief in man-made climate change and support for raising taxes on the wealthy.

The poll – which surveyed over 1,000 respondents – seems to reaffirm the findings of previous poll conducted in March of last year by Pew Research Centre, which showed 39 percent of Republicans and Republican-leaning voters supported gay marriage.