A group of 23 former Republican lawmakers, including former Defense Secretary under the Obama administration Chuck Hagel, signed a letter urging Republicans in Congress to pass a joint resolution that would terminate President Trump’s emergency declaration over the border wall.

In an open letter to GOPers, the former lawmakers argued that Congress should not allow the President to “circumvent congressional authority.” They also questioned how willing lawmakers are to undermine the Constitution.

“How much are you willing to undermine both the Constitution and the Congress in order to advance a policy outcome that by all other legitimate means is not achievable?” they wrote.

Read the letter below: