On Thursday, Republicans in the House failed to override President Donald Trump’s first two vetoes in office: a pipeline project that would bring safe drinking water to rural Colorado, and another that would return land to the Miccosukee Tribe of Indians in Florida. Their inability to block the president’s move signals their commitment to the White House over their prior support for the measures.

The Miccosukee have always considered the Florida Everglades their home. So when Republicans in Congress voted to expand the tribe’s land base under the Miccosukee Reserved Area Act—legislation that would transfer 30 acres of land in the Everglades to tribal control—the Miccosukee were thrilled. After years of work, the move would have allowed the tribe to begin environmental restoration activities in the area and better protect it from climate change impacts as extreme flooding and tropical storms threaten the land.

The act was passed on December 11, but on December 30, President Donald Trump vetoed it; one of only two vetoes made by the administration since he took office. In a statement, Trump explained that the tribe “actively sought to obstruct reasonable immigration policies that the American people decisively voted for when I was elected,” after the tribe’s July lawsuit challenging the construction of “Alligator Alcatraz,” an immigration detention center in the Everglades.

“It is rare for an administration to veto a bill for reasons wholly unrelated to the merits of the bill,” said Kevin Washburn, a law professor at University of California Berkeley Law and former assistant secretary of Indian affairs for the Department of the Interior. Washburn added that while denying land return to a tribe is a political act, Trump’s move is “highly unusual.”