Mueller's report clearly indicated criminal obstruction of justice but didn't accuse Trump of a crime because he adhered to the Justice Department opinion that a sitting president can't be indicted.

So do you support impeachment?

On one hand, it seems to not impeach is to acquiesce in the face of criminal behaviour. However, at this point, even though the House might successfully impeach, the Senate is unlikely to convict. If the Senate fails to convict, history (Clinton) indicates that it might actually strengthen Trump heading into the 2020 election.

So which is the wisest path? Is not impeaching Trump but beating him in 2020 an adequate expression of justice? Do you think 16 Republican Senators would vote to convict Trump?

Then there's also the political dimension. Elizabeth Warren (and Julián Castro) have both come out in favor of impeachment. Are the actually making the right and principled call, or are they using the issue to get some more attention?

My take:
I'd investigate but not impeach. I think soundly defeating Trump is a more forceful repudiation then impeaching and not convicting. While it's tempting to indict Trump after he leaves office, I think this is a bad precedent to set and will continue to tear at our political fabric.

I think Warren's support for impeachment is either an expression of her warrior spirit or a cynical ploy for more attention, both of which I don't support. However, I am glad for to be getting more attention and I hope that expands to her substantial policy proposals.