WASHINGTON — The tentative deal reached late Monday by congressional negotiators to avert another government shutdown brought to the fore something President Trump has rarely seen in his time in office: reality-based programming.

With Mr. Trump holding firm to his demand for a border wall with Mexico, Republicans and Democrats on Capitol Hill adopted another approach, namely flexibility.

The agreement in principle is a new challenge for Mr. Trump as he navigates a divided government.

Here are some key takeaways from the possible accord.

Mr. Trump has rarely wavered in his arguments for a border wall, many of them false, including several of those made Monday night at a campaign rally in El Paso.