You assume much by saying most want a wall. In fact, it's a statement that you can't really make with any authority, unless your "us" is your group of friends and acquaintances.
There have been several polls on the subject, with varying degrees of accuracy and viability. The one I'm most likely to believe (I have been VERY wary of the accuracy of polls since 2016, so I don't fully trust any of them) was done in February of this year by Quinnipiac, which showed an overall opposition to the wall (59% opposed to 37% support). It showed 75% support among Republicans, and 89% opposed among Democrats.
What's interesting to me is that, when confronted with a $25 Bil price tag (which is a low-balling of what it'll cost), those numbers changed to 65% opposed and 33% support. I'm sure public opinion has changed since February, but not nearly enough for it to qualify your statement.
So maybe the lawmakers who are opposed to the wall, at least in this particular instance, are actually doing their job by representing their constituents.