The border wall is one of President Trump's best known campaign promises, and it's the reason we're in a partial government shutdown — but the Associated Press has a good roundup of comments by White House officials and allies that suggest it might end up being less than a complete physical wall between the U.S. and Mexico.

Between the lines: It's not surprising that Trump allies would float ideas to negotiate Trump's promise down to something he just calls a wall. But given how important Trump's promise is to his supporters, nothing will be resolved until Trump himself signs off on something less.

The key comments, per AP: