The emerging consensus among acting chief of staff Mick Mulvaney and top budget officials is to shift money from two Army Corps of Engineers’ flood control projects in Northern California, as well as from disaster relief funds intended for California and Puerto Rico. The plan will also tap unspent Department of Defense funds for military construction, like family housing or infrastructure for military bases, according to three sources familiar with the negotiations…

But the strategy is far from a cure-all for a president with no good options, and it has already sparked debate within the White House. Moving funds by executive order is virtually certain to draw instant court challenges, with opponents, including some powerful members of Congress, arguing the president is encroaching on the legislative branch’s constitutional power to appropriate funds.

Some Trump officials, including those aligned with senior adviser Stephen Miller, have argued internally that the gambit might be even more vulnerable to court challenges than a national emergency declaration. And in a sign of the political fallout, the top Republican on the House Armed Services Committee has argued that tapping military construction money would hurt the armed forces’ potential readiness.