If they wish to fill them out, they will also need to successfully forge the voters' signatures. Ballot envelopes with signatures that don't match that of the voter get turned over the District Attorney.
Right. Dems would still do it even if the signature didn’t match. I would expect they would ask the ballot holders to sign the envelope before turning over the ballot.
BTW, I dropped off my CO vote about 3 hours ago in the county clerk drop box. Another vote for Trump. :)