Trump asked for an investigation into corruption, nothing illegal about that and we've discussed that. Now we can debate motive, personally I think the guy (as I've stated before) let's his emotions get to him, like a 12 yr old sometimes, and he can't let things go. With that said he is still furious over the fake dossier and DNC corruption that tried to sink his election before he was ever elected back in 2016. I'm sure he resents Biden/Obama/Clinton's for the 2016 issues and I think he was hoping this investigation by Ukraine (because the DNC corruption issues went through Ukraine's own corrupt political highways at that time) would also dig up items on the Clinton's and shed light on the DNC corruption (and it still might, or would if the current Dem crowd didn't bamboozle it with a trumped up impeachment allegation). The left talking points are this, that his actions are directly linked to the 2020 elections, if his actions and his intent were proven to be entirely based on tampering with the 2020 elections then let's escort him out the door. I just don't think that's what his intent was, he's mad and he wants the corruption investigated. You've stated before if he was looking into corruption than why isn't he investigating others not just Biden, well if his intent is to tamper with the 2020 elections than why is he just investigating Biden and not Sanders, Warren, Harris, Booker, etc? Argument goes both ways.
If any other president was in office other than Trump and they were investigating corruption of Gov't officials you and many others would be applauding it.
As to the WB and his political bias, yeah it matters because it shows a heavily left biased process from day one and regardless of what other facts may come out, it taints that process, taints those statements, facts, going forward at least in the minds of the general public. Fruit of the poison tree if you will. Most don't trust the process anyway and add the fact that the guy who initiated the whole allegation was after Trump from day one and involved in 2016 tactics to oust Trump then, well will not sit well with many. No wonder the Dems have been trying to conceal this guy and protect him to no end.