It's harvest time in Colorado, and not just for pumpkins. Concerns are running high over door-to-door campaign workers asking voters for their mail-in ballots in what is known as "ballot harvesting."

Now that all-mail voting is the law of the land in Colorado, the challenge for campaigns is to persuade voters to drop off or mail in their ballots — or hand them to the foot soldiers who turn up on their doorsteps offering to do it for them....