A Supreme Court decision to allow President Trump to redirect $2.5 billion in Pentagon funds towards his long promised border wall will "really accelerate" progress on the project, according to Acting DHS Secretary Kevin McAleenan in Sunday appearance on Fox News.

The 5-4 decision will allow for the construction of more than 100 miles of fencing - the most significant step yet, according to Bloomberg.

McAleenan said while the court’s ruling was “a big victory” to build more of the wall, “we do remain in the midst of a border security crisis” with migrants flooding the region and that Congress must take more action to deter crossings. “We made very clear the targeted changes in law that we need,” McAleenan said. -Bloomberg

In Friday's order, the Supreme Court said that the government made a "sufficient showing" that several groups challenging the decision had insufficient grounds to bring a lawsuit against President Trump's Feb. 15 national emergency to fund the wall without congressional approval.

"Today’s decision to permit the diversion of military funds for border wall construction will wall off and destroy communities, public lands, and waters in California, New Mexico, and Arizona," said Sierra Club attorney GLoria Smith.

Trump, meanwhile, took a victory lap - tweeting "Wow! Big VICTORY on the Wall," adding "Big WIN for Border Security and the Rule of Law!"

Wow! Big VICTORY on the Wall. The United States Supreme Court overturns lower court injunction, allows Southern Border Wall to proceed. Big WIN for Border Security and the Rule of Law! — Donald J. Trump (@realDonaldTrump) July 26, 2019

The wall segments in Arizona, New Mexico and California would give Trump a tangible achievement to tout in his re-election campaign. Until now, congressional and court resistance had thwarted significant progress toward a stronger barrier on the almost 2,000-mile frontier. During his campaign, Trump said Mexico would pay for the wall. On Saturday he said the U.S. would be “fully reimbursed for this expenditure, over time, by other countries.” He didn’t say how. -Bloomberg

"This is not over," said the ACLU's lead lawyer, Dror Ladin. "We will be asking the federal appeals court to expedite the ongoing appeals proceeding to halt the irreversible and imminent damage from Trump’s border wall."

That said, even Bloomberg has to admit: "the court’s unsigned order suggested the administration was likely to win the fight. The order said the administration “has made a sufficient showing at this stage” that the groups don’t have the legal right to challenge the Pentagon’s spending decisions."