Let's put it this way and assume Devil's advocate. Let's say Trump was found guilty of the Ukraine stuff you mentioned. Since Hillary and Obama got a pass for all the things they did that broke the law or that were highly questionable (and there are a ton), should Trump? If Trump gets the justice he deserves then shouldn't Hillary and Obama also receive the same intense scrutiny that he has?
I think the issue a lot of people have (myself included) is you have a double standard when it comes to politicians. Even before Trump won as president the liberal base was already planning ahead and gearing up to try to find a crime he committed so they can remove him from office. That's an incredibly dangerous precedent to set just because you don't like someone's policies, words or actions. A person should only be investigated when there is something of serious concern and one party should NEVER go looking for a crime to find like the democrats have been doing since before he won the election. There were lots of questionable things during Obama's term but we didn't go through 8 years of investigations and attempts at impeachment because Republicans didn't like him or his policies. Republicans didn't launch a ton of investigations trying to find a crime or wrongdoing. There's also a sense by many of a double standard when people like Obama and Hillary have multiple issues that are highly questionable or should be heavily investigated but aren't... or if they are they get a pass like Hillary did in her email scandal. When people see them getting away with the kind of stuff they did and no repercussions is it no surprise that Trump supporters would want the same "fair" outcome for their guy? If Obama and Hillary got away with it, why not Trump too? Why should Trump get "justice" but Hillary and Obama get a pass? If we are going to seek justice, which path is the correct one to take? Do you lock all 3 up to get "justice" or give 2 of them a pass and lock the Republican up? Which is fair, just and consistent? This isn't to justify anything he's done but simply to look at it from a logical standpoint; if the law and justice is going to be avoided for Hillary and Obama then Trump should get the exact same treatment or if he goes to jail Hillary and Obama should be heavily investigated and sent to jail too. Also, this is all assuming one can actually prove he broke the law which hasn't happened at this time.
Last but not least, many Trump supporters are in favor of his policies and not his words/actions. The conservatives he has put in the Supreme Court make decisions throughout the year that affect our constitutional rights and are arguably as important, if not more than, a president is since the courts have so much power these days. What about all the other judges he has put in who are ones who will help uphold constitutional freedoms?
It's more than a "Trump bad" mentality it's looking at the big picture... not to mention in 2020 the alternative to Trump is likely going to be a socialist and just look at Venezuela to see how that ends up. Do you really want America to become like that? California is already halfway to third world status with their diseases rampant (like leprosy and typhus fever to name a few), rolling power outages due to mismanaged govt funds and green policies, corruption, and an out of control homeless population.
Regarding the overall Trump support I actually think it's higher than in 2020. Unemployment is at incredibly low levels and as Bill Clinton used to say "it's the economy stupid." Now if it crashes before the 2020 election that will probably hurt Trump more than anything else but as of now I think his support base is probably at higher levels than 2016. Just look at the fundraising money he's bringing in. I also know Wall Street doesn't want a socialist winning for obvious reasons so they might even back Trump depending on who the 2020 Dem candidate ends up being. This is my 2 cents on the topics discussed but it's great we live in a FREE country that men and women sacrificed their lives so that we can have choices, debate in a civil manner and celebrate the freedoms we do have.
