The Treasury's decision to allow gay couples to file join tax returns grossly oversteps the department's authority, the National Organization of Marriage's Chris Plante charged in an exclusive Newsmax interview.
But the decision came as no surprise as President Barack Obama's administration continues on its path to legalizing gay marriage throughout the country.
Editor's Note: Should ObamaCare Be Repealed? Vote in Urgent National Poll
Now the only way to stop such a situation is by way of a constitutional amendment specifically setting out that marriage should only be between one man and one woman, said Plante, the NOM's communications director.
Story continues below video.
"The fact is, the Treasury Department has grossly overstepped its authority," Plante told Newsmax TV. "It's up to Congress to create the laws. While they claim to be trying to create uniformity in federal law, as opposed to taxes, it was the exact same rationale that led them to the Defense of Marriage Act decision this summer, and they stand in conflict with each other.
"This is a gross misstep by the administration."
Plante said the administration must expect lawsuits in the wake of the decision announced Thursday to allow same-sex couples to file jointly even in states that have constitutions that ban gay marriage.
"There will be a myriad of lawsuits," he predicted.
"This ruling creates all sorts of confusion and it will result in lawsuits, it will result in states not sure what to do, and the fact of the matter is states do have the right to define marriage as they see fit. That is still in Section 2 of the Defense of Marriage Act.
"This is the Treasury Department going outside the bounds of its own authority, but we're not surprised by this," Plante said. "The president himself and the Department of Justice failed to defend the Defense of Marriage Act in the beginning in the First Circuit Court of Appeals, so they've already abdicated their role.
"It is part-and-parcel of a movement that we're seeing across the country for administrators, or bureaucrats, or county clerks, even, to take the law into their own hands and try to redefine marriage," Plante said.
He said the confusion calls out for a federal constitutional amendment. "We cannot have 50 definitions of marriage across the country. Marriage has predated the United States. It has been a presumed one-man and one-woman institution until just 2000, when this idea of redefining marriage entered Western civilization and Western thought.
"It is ludicrous that we're at this point," he added. "We need to define marriage as one man and one woman not because we are actually creating it but because that's what it is and government has a purpose investing in marriage as one man and one woman because it creates the best place to raise children and the next generation."
Editor's Note: ObamaCare Is About to Strike Are You Prepared?
But in the meantime before an amendment can be passed, Plante said indifividual states have to protect straight marriage. " Indiana, for example, will have a valid amendment in November of 2014 to define marriage as one man and one woman. We heartily support that."
© 2014 Newsmax. All rights reserved.