You're not "hiding behind the finer points of the law". It's the law. Period. Unless we devolve into an autocracy, the law matters.

As for national security, both sides are concerned about that. I wouldn't say most Republicans aren't (maybe a few aren't...like Trump). This isn't much of a national security issue. People entering US soil and requesting asylum is not a national security issue. The "gotaways" arguably are. We'll have those no matter what you do; people whom have no intention of requesting asylum. That used to be the majority of those crossing the border, but that hasn't been true for at least a decade, probably longer.

As for losing votes, maybe when Trump isn't running. For now, most of those votes are quite secure. Trump has alienated them bigly.

Also, living in AZ, I can tell you that Latino folks are not fond of all the attempts to "seal the border". In fact, many (most?) didn't like this bill. You do know that the Hispanic Caucus was completely excluded from the negotiations, yes? Because they weren't going to like giving up anything.