You need another test to extract the alcohol as the only variable. We need another 160 solves with a shot of water every 20. By comparing the two we can cancel out mind/finger fatigue from the results. Any time differences left should only be from the alcohol.

Ideally that's true. And I'm sure for some individuals it is how they act.

In general politicians vote for things that keep themselves in power, which means avoiding things that piss the public off enough for them to take action. If the public is annoyed but doesn't actually do anything the politicians are safe to continue doing what they want.

We can. But there is no strong incentive for politicians to do that. Both sides like the current manual process because either it's in their favor and they win, or they lose but they can stir up rumors that the vote was rigged. Either way the politician remains relevant in the public's mind.