The problem with any accusation of the sort is that you run into the argument that what one considers obstruction, others just consider execution of Presidential power.
The only two previous impeachments were for specific acts. For Johnson it was violation of the Tenure of Office act. For Clinton, lying under oath.
Even with the other items added, all of the articles flowed through those two specific actions.
So far we have not seen anything concrete as this with regards to Trump.
Ahh yes, so when the President wanted Flynn's investigation to be squashed by Comey, he was actually acting as a good ol' steward of law, not a corrupt asshole trying to get his GUILTY AS HELL man off the hook.
When he fired Comey under false pretenses, only to later admit that it was actually over the "Russia thing" he was just being a good cop...who had to lie his ass off to the public.
When he ordered WH laywer to begin the process for removal of Special Investigator, he was just trying to help the justice process along.
When he ordered the entry of false records to cover up his efforts to get Mueller removed, he was just doing the right thing.
When he told Attorney General Sessions to ignore DOJ council, un-recuse himself and limit the scope of Special Investigation to only future elections, he was definetly not tending to his own personal interests.
...do you seriously belive such horseshit?
If this was actually letigated in court any jury would convict Trump in all of half an hour on these charges.