WEST DES MOINES, IOWA ? Kansas Sen. Sam Brownback, among the most conservative of the potential Republican presidential candidates, said Tuesday there’s room in the GOP for candidates who favor gay rights, but he warned that such politicians wouldn’t be welcomed by the party’s conservative base.

“It’s a big-tent party and has been for a long period of time, particularly since Ronald Reagan talked about this being a party of different viewpoints,” said Brownback. “If somebody agrees with you 80 percent of the time, he’s not your enemy.”

Brownback, in the midst of another visit to Iowa, was asked about criticism that Massachusetts Gov. Mitt Romney was getting from conservatives over his writings years ago that suggested he backed gay rights.

While there’s room in the party for such candidates, they will face a tough sell with conservatives focused on social and religious issues, said Brownback, who hopes to base his bid for the GOP nomination on such voters.

Asked if favoring gay rights would doom a candidate in the GOP primary season, Brownback said: “I don’t know about that. I mean, where are you on taxes? The base of the party is issue-oriented and issue-driven, so those are significant things.”

Brownback said it’s far too early to dismiss candidates because of their views on volatile issues such as gay rights.

“We are way, way early in this process, so I wouldn’t rule anybody out or in at this point in time,” said Brownback.

Brownback has made several visits to Iowa, where precinct caucuses launch the presidential nominating process. On Tuesday, he held private meetings with key activists before attending a Christmas party with local Republicans.

Brownback last week announced he was forming an exploratory committee allowing him to travel and raise money as he explores the potential of seeking the GOP nomination. The day after he announced the formation of that committee, he met with Republican activists in eastern Iowa and vowed to campaign heavily in the state.