Jr's meeting is not the impeachable offence and I apologize for not being clearer.  There are three separate probes into Trump's relationship with Russia and Jr lying about a meeting intended to get Democrat dirt is just one more piece of evidence pointing to Trump's inner circle colluding with the Russians to subvert the electoral process.

The odour coming from Russia is far from good, and I truly believe it will hurt Trump badly once Mueller et al uncover the source of the stench.