Only One

Trump, whose front-runner status in the Republican presidential race has solidified his leadership of the GOP, has loudly vowed to kill the bipartisan border deal.
Trump, House Republicans plot to kill border deal

If the problem that House Speaker Mike Johnson (who appears to be speaking now on behalf of Donald Trump) has with the current legislation is that "it wouldn't do enough to stop illegal border crossings," one would suspect that the answer would be to either add amendments to shore up that part of things, or simply pass another bill later. I would not be surprised if the problem that Mr. Trump (and thus, the Republican leadership) has with the plan currently under consideration is that it would hand a legislative win to President Biden, and take immigration out of the mix of issues for Mr. Trump to run on in the summer and fall. He supposedly wants a "perfect" immigration bill, and is calling on Republicans in the House of Representatives to block anything less. Of course, no details of this "perfect" legislation have been provided to anyone.

But such is the nature of partisanship. If Donald Trump is elected to a second term in office this fall, he won't actually need to do anything with the border. The Republicans are unlikely to obtain sixty seats in the Senate, and that means that Democratic senators will be able to block legislation that they don't like. And it's hard to see them wanting to play ball with a Trump Administration again. And since Republican voters will blame Democrats for any problems, legislation or none, Mr. Trump could respond to difficulties in passing legislation by not bothering to have any such legislation put forth. Given this, I suspect he's more invested in blocking progress now than making progress later. Otherwise, there's no real reason to literally let the "perfect" be the enemy of the good.