I wasn't around for the impeachment inquiry into President Nixon, but from all I've seen/heard about it, there was clear an overwhelming evidence that Nixon displayed what might be called a blatant disregard for the rule of law (and there were some 18 minutes of recordings which put him dead to rights on that), enough so that the effort to remove him from office was bipartisan and Nixon saw no alternative but to resign. I'm not seeing that in President Trump's case.
A couple thoughts/questions re: "Treason, bribery, and other high crimes and misdemeanors" and the specifics of Trump's case:
Assume you're not a partisan piece of shit; reverse the party affiliations if necessary and see if you come out with the same answer in either case:
Are treason, bribery or other high crimes and misdemeanors sufficient grounds for impeachment, or or only necessary or potential grounds? Of course, the Framers sought to have some mechanism by which a sitting President could be removed.
In the case of President Clinton, he committed perjury in a deposition and perhaps before a grand jury as well. He tried to influence the testimony of his assistant Betty Currie. For such actions this national chief law-enforcement official was deemed by the Arkansas State Bar unfit to practice law. Is this sufficient to warrant impeachment and/or removal? Does it make a difference if these actions fall under the heading of "high crimes and misdemeanors"? Was Clinton displaying a blatant disregard for the rule of law? (Should blatant disregard for the rule of law suffice as an impeachable/removable offense? I would think so; if that doesn't suffice, then what does?)
As for the specifics of Trump's case: Some reasoning I've heard for why his payoffs to Stormy Daniels weren't a violation of campaign finance laws is that he could have other, legitimate reasons for such a payoff (e.g., to avoid personal embarrassment). So we might call this a dual-motivation excuse. Does such a dual motivation exist in the case of Trump's pressuring Ukraine to announce investigations of the Bidens? Supposedly Ukraine announcing/initiating investigations would benefit Trump and hurt Biden politically, but Trump has said that his concern isn't political but is about corruption (particularly if there is probable cause to think corruption might have taken place).
Was there probable cause to suspect corruption by either of the Bidens? Trump told Zelensky that Biden using monetary pressure against Ukraine to get a prosecutor not to investigate Burisma "sounds terrible to me [Trump]." What now?
Supposedly, a foreign country (or whomever!...) announcing an investigation of X tends to be politically harmful to X, whether or not anything is ever actually dug up. Well, gee. What do you think the Demo-rats & allies/enablers were up to when it came to the Mueller investigation that had been hanging over the Trump presidency some two years? What was their intent other than to go after something that "sounds terrible to [them]" when there was nothing there? What the fuck else were the likes of Adam Schiff doing those two years other than casting baseless suspicions on the Trump presidency?
On a matter of broader political interest: how much cynicism does it take to assume - as apparently is assumed inside the Beltway - that so much as an announcement of an investigation of X tends to be politically harmful to X, whether or not anything is ever actually dug up? Wherever did they get that idea? How does the Demo-rat complaint about Trump pressuring someone to investigate his political opponent not amount to the ultimate in cynicsm if not blatant hypocrisy? (Keep in mind that as far as I am concerned, the Demo-rats have squandered all credibility and grounds for good will; a number of their top "leaders" in Congress and on the '20 campaign trail have claimed that there are sufficient grounds to impeach Brett Kavanaugh, for example - not a position an honest and informed person would take. They've recklessly smeared Trump and his supporters as racists, for another example. If you're looking for honest and credible arguments for whether Trump should be impeached/removed, the Demo-rats cannot be considered a reliable source. Any reasonable observer should also note the Demo-rats' years-long effort to run interference and make excuses for Obama/Comey's FISA-abusing FBI.)
As for Trump, if he really thinks he did noting wrong, then I don't see any excuse whatsoever for him to hide behind anyone or anything when it comes to his (presumed) Senate trial. He should get his fat fucking ass up there to Capitol Hill to testify in person (under oath, etc.) and clear his name. He should face the adversarial grilling of Senators. Likewise, Joe Biden should also stop being an evader and explain just what the fuck his unqualified, black-sheep son was doing drawing some $50k a month from a company (for doing what?) that apparently plays a key role in the Ukraine narrative (enough so to draw his intervention as VP and Ukraine point-man...).
On a matter of broader political interest: how much cynicism does it take to assume - as apparently is assumed inside the Beltway - that so much as an announcement of an investigation of X tends to be politically harmful to X, whether or not anything is ever actually dug up? Wherever did they get that idea? How does the Demo-rat complaint about Trump pressuring someone to investigate his political opponent not amount to the ultimate in cynicsm if not blatant hypocrisy? (Keep in mind that as far as I am concerned, the Demo-rats have squandered all credibility and grounds for good will; a number of their top "leaders" in Congress and on the '20 campaign trail have claimed that there are sufficient grounds to impeach Brett Kavanaugh, for example - not a position an honest and informed person would take. They've recklessly smeared Trump and his supporters as racists, for another example. If you're looking for honest and credible arguments for whether Trump should be impeached/removed, the Demo-rats cannot be considered a reliable source. Any reasonable observer should also note the Demo-rats' years-long effort to run interference and make excuses for Obama/Comey's FISA-abusing FBI.)
As for Trump, if he really thinks he did noting wrong, then I don't see any excuse whatsoever for him to hide behind anyone or anything when it comes to his (presumed) Senate trial. He should get his fat fucking ass up there to Capitol Hill to testify in person (under oath, etc.) and clear his name. He should face the adversarial grilling of Senators. Likewise, Joe Biden should also stop being an evader and explain just what the fuck his unqualified, black-sheep son was doing drawing some $50k a month from a company (for doing what?) that apparently plays a key role in the Ukraine narrative (enough so to draw his intervention as VP and Ukraine point-man...).
For reasons apparent to most any honest and attentive observer, this impeachment process has been and is expected to continue being a blatantly partisan event that probably serves to illustrate Beltway intellectual and moral bankruptcy and cynicism than anything else, with the impeaching party having squandered all credibility/trust on tons of matters. Trump was elected for, among other things, being as credible a vehicle as anyone - as a take-no-prisoners outsider - to clean up the Beltway swamp. (If he doesn't do it, who credibly could? I already know what happened in the case of Obama. Ironically, his original "clean up Washington" persona was starting to crack when as Senator he voted back in '08 for FISA powers, as the likes of Glenn Greenwald would surely not overlook...)
Well, that's why Trump should testify and clear up just why it was within his constitutional powers to pressure Ukraine as he did, and released the funds when he did (i.e., two days after word of the whistleblower got out). And since the Demo-rats have no reputation left over to salvage, it's up to the GOP to honorably follow the evidence where it leads, and weigh the input of Dershowitz (e.g.) alongside that of the law professors who testified to the House Judiciary committee. Such dialectically responsible behavior is a requirement of basic epistemic justice.
The American people (the ones with a clue, that is) are fucking sick and tired of being subjected to much less from their "leaders," and thereby having their intelligence and character routinely insulted.