For them, looking into whether the Russian investigation was a "hoax," is OK.
But the Biden stuff is bad.
They seem to be missing a piece of Giuliani's crackpot theory ...
The two investigations are one and the same, as @rgoodlaw explains: justsecurity.org/66658/the-miss…
So, don't act so surprised when faced with the question.
Because Trump's supporters are now trying to make the case that somehow a quid pro quo (using US military aid) tied to an investigation of the DNC/2016 election is fine (ignoring the fact that the DNC is also Trump's political rival) ...
But they are missing a piece of their own wackadoo Ukraine/2016 story, which is that, according to Giuliani (who's been running the show at Trump's request), Biden is a key figure.