A recent Politico/Morning Consult poll found that 70 percent of Republicans said they would be more likely to vote for a senator or representative who supports Trump’s national emergency declaration.

“The reason why you had Gardner and Tillis do this is because they knew that the process/principle argument wasn’t going to fly with the Republican base when this is their No. 1 issue. They want execution, and they don’t care how you get it,” said Ford O’Connell, a Republican strategist.

O’Connell said Gardner and Tillis, who have two of the most competitive races next year, need to worry about fending off primary challenges and turning out conservative voters in the election, when Democratic turnout is expected to be high.

“Even though they want to fend off primary challenges, this is also a situation where, in the general election, if they cross Trump on this issue, Trump could win their state and they could still lose,” he added. “In a lot of these races, it’s going to be two-point races, whether it’s Gardner or it’s Tillis.