The candidate that does the least harm would probably be Cornell West or Jill Stein. voting for the senator who put in place the conditions for roe v Wade to be turned over, the senator who confirmed some of those very same justices, to be president does not reduce harm. if you won’t take it from me maybe it’ll take it from this guy
https://www.indigenousaction.org/voting-is-not-harm-reduction-an-indigenous-perspective/
harm reduction as a specific thing. The best example of it is needle exchanges and safe injection rooms for addicts. you recognize that the bad thing is happening, and you do what you can to mitigate the harm that comes from the bad thing. The bad thing is bad people being in power. what you can do to mitigate that is engaging in mutual aid and community organizing around issues that are affecting you locally. voting for a Democrat or Republican won’t stop the bad things from happening. The Democrats have brought us to the point where Trump is seen as reasonable by half the electorate. The Democrats have shared power with the Republicans for the past hundred years as fascism has taken over the government. voting for them doesn’t reduce the harm that they cause.
edit
voting for Democrats is like giving out free Suboxone and saying at least it’s not heroin. That’s not harm reduction. harm reduction is recognizing that the addicts are going to use the substance of their choice and making that as safe as possible.
harm reduction is a specific strategy, and voting is not harm reduction.