You're Independent? I don't think the Independence Party has anyone on the ballot.
You probably mean unaffiliated.
Unaffiliated voters can now vote in primaries in Colorado, which is silly, but that is an entirely different petard to be hoisted upon.
To answer the question, I don't think any Democrat candidate can upset the President, barring a catastrophic event.
I was talking today with a politically savvy character that worked in the Colorado House for a while and asked him about a sabotage primary vote, much like what you are thinking. It came down to "it doesn't matter".
The Democrats will push the candidate that will be most electable to the front, much like they did in 2016. Remember super delegates?
Those were the "voters" that gave Clinton the nomination ahead of Sanders.