As emergencies go, the impasse between migrants and the U.S., which is being played out along the Texas border, was not enough of a crisis to gain every Republican’s support for President Trump’s plans to fund wall construction. Not this year.

The president, rebuffed in this year’s federal budget for building a border wall, was hellbent on using his emergency powers to spend the money Congress would not appropriate. That was his plan B.

While Texas’ two senators, John Cornyn and Ted Cruz, voted with the president, a dozen Republican senators joined Democrats to shoot down Trump’s emergency funding plan. The president plans a veto, he said in a Thursday tweet.

Even among Trump supporters, there was an obvious discomfort. Some suggested Congress has a role in appropriating federal funds in the budget, and they believed the president was making an end run around their constitutional authority.

There is politics and then there are principles.

U.S. Sen. John Cornyn, R-Texas, told Texas reporters during a Wednesday conference call that he supports President Trump’s battle to protect the nation’s southern border, but said he would join a Senate colleague’s effort to give Congress “a stronger voice” in the future under the National Emergencies Act the president intended to use.

Cornyn has expressed skepticism about the president’s continuing effort to use the emergency power to bypass Congress and fund construction of a border wall. Cornyn said he believes the regular appropriations process, which by the Constitution gives Congress the power of the purse, is appropriate and ought to be followed.

Is there an emergency at the border? Cornyn says yes. Caravans of migrants, citing political cruelty in their home countries and pressing to enter the U.S., have overwhelmed the capability of the Border Patrol both to meet the migrants’ emergencies and protect the border.

Further, the urgency to tend to migrants’ humanitarian needs has given drug cartels some opportunities to send illegal drugs into the U.S. and to force migrants into involuntary servitude, especially as sex slaves.

U.S. Sen. Mike Lee, R-Utah, had sought compromise legislation to give Congress a stronger future voice under the National Emergencies Act, but Trump shot down that idea.

Unlike Cornyn, an exasperated Lee suggested that the president is “acting like a king” and to prevent that, the Senate should stand up to him.

In the end, a dozen Republicans felt the same way or stronger than Lee, who eventually voted to support Trump. Instead of overwhelming the Democrats, Trump split his own party. Some of the president’s supporters are talking retaliation.

Better that everybody move on to the next issue. Politics is the art of coalition building. In this case, the president couldn’t build one. Maybe he was wrong.