IMO, the only reason that impeachment proceedings haven't started is that Nancy Pelosi has blocked all attempts so far out of some ill-conceived strategy, not because there's a lack of evidence.
Heck - Trump has been doing impeachable things out in the open ever since his inauguration. He never bothered to remove himself from business relationships that violate the emoluments clause.
Since then, though, the many times he committed obstruction of justice are now well-documented and impeachable as well. It's also become clear that he would have been guilty of even more serious crimes if it weren't for his staff's failure to follow illegal orders on several occasions.
I'm not sure what Pelosi's strategy actually is here. The obvious answer seems to be that they simply don't have enough votes in the Senate to carry it through. Other than that, it seems that they're just going to wait until the election and let the voters decide whether to keep Trump or dump him. Impeachment proceedings would be counterproductive at this point.
In Nixon's case, they found the "smoking gun" which was enough for a conviction, so that even his own party was turning against him. They just couldn't protect him anymore, even if they wanted to. Plus, the Democrats had a majority in both houses of Congress at the time. Even Goldwater had to go in and see Nixon to convince him to face reality.
I think the abuses at the border will mobilize more Democrats to the polls, so I expect that Trump will do worse than he did in 2016, when he did lose the popular vote.
A lot of depends on the Democrats themselves. I sense a certain level of "obsession" over Trump and wanting to defeat Trump - something so strong that it may be clouding their judgment and objectivity. They're squabbling with each other, too.
It somewhat reminds me of Al Pacino's ending monologue in the film
And Justice For All:
That man there wants a win so badly today, it means so much to him, he is so carried away with the prospect of winning, the idea, that he forgot something absolutely essential to today’s proceeding. He forgot his case. He forgot to bring it. I don’t know, I don’t see it, do you? The prosecution’s case. He’s got to have one.
Of course, the scenario here is that Pacino's character hates the judge more than the prosecutor does. He wants to see the judge go down, but he was being coerced to defend the judge when he didn't want to. He was probably also mad at the prosecutor for bringing such a weak case that made his job almost too easy.
I would hope that members of the military would care about things like duty, honour, and protecting the Constitution... but I would have also hoped that border agents would care about human rights laws and basic decency.
Concepts like "duty" and "honor" are somewhat subjective and open to interpretation, just as the Constitution is also subject to interpretation. If you get the right lawyers and the right judges in key positions, just about anything is possible. We already have a strong underlying militaristic, ultra-patriotic bent, so there are large segments of the population geared in that direction already.
As for the Border Patrol, they've always had a somewhat spotty reputation. Recently, there have been articles in which their private facebook pages have been outed and some disturbing comments revealed. There's something about the overall culture of the Border Patrol, which was brought up recently in a trial for a Border Patrol agent accused of running over a Guatemalan man.
That, and various patterns of misconduct discernible in police departments across the country, as well as criminal acts by military personnel. And then there's all the things we know and don't know about our intelligence agencies. These are not nice people we're talking about here.
