"The people of Iowa reject the redefinition of marriage, and I pledge today to defend the bond of marriage, as I have consistently done in the past," Brownback, who came in third in the recent Iowa straw poll, said according to AP.
Meanwhile, republican frontrunner former New York mayor Rudy Giuliani rejected gay "marriage" but supports limited recognition of same-sex couples.
Top democratic presidential contenders Sen. Hillary Rodham Clinton (D-N.Y.) and Sen. Barack Obama (D-Ill.) responded that although they are in favor of civil unions, they leave same-sex "marriage" laws up to the state to decide.
Since last Thursday's ruling, some 20 same-sex couples applied for marriage licenses in Polk Country before Hanson issued a stay on his decision Friday.
Several prominent Christian groups have condemned the Iowa ruling, in which the country judge claimed that Iowa's 1998 Defense of Marriage Act - which allows marriage only between a man and a woman - was unconstitutional and marriage laws must be interpreted as gender neutral so as to recognize same-sex "marriage."
"This decision demonstrates that judicial activism is still a problem," said Family Research Council's president, Tony Perkins, in a statement. "For a judge to have 'nullified, severed, and stricken' from the law the definition of marriage inherent in both tradition and statute is an outrageous act of judicial activism."
Perkins urged Iowans to respond by passing a state constitutional amendment to define marriage as a union between a man and a woman.
"That's the only sure way to protect the institution of marriage from radical social engineering by state judges," said the pro-family conservative leader.
Other Christian groups which have condemned Judge Hanson's ruling include Concerned Women for America, the Baptist Convention of Iowa, and the Iowa Family Policy Center.
