Sorry Trump haters...

but there is no "evidence" of the President being unfit for office

Let's start with the ground rules. The bar for determining a President to be "unfit for office" or "incapable of performing the duties" would need to be set fairly high. Certainly it would require at least a "preponderance of evidence" - if not evidence that shows some form of incompetency beyond a "reasonable doubt". Moreover, this sort of situation (where you wish to undo the results of an election) would require some form of evidentiary hearing (either formal or informal) that would be on par with what we might see in court of law.

Given those ground rules (and I fail to see why anyone would argue them considering the stakes) it would be literally fair to say that there is actually no evidence to support the assumption that the President is either unfit or otherwise incapable of competently performing the duties of the President.

But wait!! What about all of those stories? Bob Woodward has a book coming out. The NY Times just published an Ed/Op from a "senior member of the Trump administration". The internet is "dripping" with accounts of incompetency and unhinged actions. Well without getting into the fact that the NY Times once described an unpaid intern as a "senior member of the Trump administration" the reality is that none of that is evidence. At best it's hearsay, and at worst is fiction.

To be clear, even the Ed/Op is the NY Times repeating (publishing) what someone provided for them. That makes it hearsay if for instance the editor of the NY Times was willing to come testify. On top of that, quite literally everything alleged in the story was another layer of hearsay (second hand information provided to the author). Lastly, the author is unidentified, meaning there is literally no witness testimony. Similarly the book by Woodward will be all hearsay. Likely hearsay of hearsay. Likely anonymous as well.

Why isn't "hearsay" allowed into court procedures? Well for starters, it's wildly unreliable. But most importantly because there is no opportunity to question the actual witness to the events, much less cross examine them. In court, you are generally (with very rare exceptions) only allowed to present witnesses who have first hand accounts of events. Those witness provide their testimony and the defense would then have a chance to cross examine and question them.

Imagine a Judge allowing a reporter to testify as to what an unidentified source told them. Imagine the unidentified source was actually using information gathered from another unidentified source. Imagine a Judge allowing double unidentified hearsay. It would never happen, and it would never happen for good reason.

What Trump haters have right now is not evidence. What they have are unproven allegations, with almost no tangible manner in which to prove them. Moreover, pretty much every allegation that has been made in the media has been denied by those who actually have first hand knowledge of whether or not something might have happened.

Would anyone sitting on a jury, ignore the open testimony of people who had first hand knowledge of a situation, and instead take the word of someone else who claims that another unidentified person "told them" that something happened? How about if that unidentified person was actually providing information told to "them" by a third unidentified person. Would you trust double unidentified hearsay over the first hand accounts of the actual people involved?

Of course not. Not unless you are the one who is actually dangerously unhinged, irrational, and incompetent... or perhaps if you are suffering from Trump derangement syndrome.