“It is the Trumpist revolution,” adds Paul Rosenzweig, a fellow at the R Street Institute, a center-right public policy firm. A longtime conservative who now registers as an independent, Mr. Rosenzweig is disappointed that so many Republican members are supporting the president’s actions, which he sees as counter to the bedrock values of a true conservative.

“The party’s response to this exercise is either the death knell for it being taken as a serious party of principle or a demonstration that it’s really all about winning and they don’t have principles at all,” Rosenzweig says.

Still, other conservatives say all the hand-wringing is overwrought. While not thrilled with the president’s use of executive power – “ ‘supportive’ would be a little bit strong,” says the Heritage Foundation’s John Malcolm – he’s also not too concerned that Democrats could easily use the same move in the future.

The emergency declaration only started the ball rolling, Mr. Malcolm says.