If you take away people's vote to change things then what you are saying is "The only way you can change things is by protests or violence."
You can bend the rules, or plausibly misunderstand them, or put unfair ones in place (using other rules), but once you make it impossible for people to have a say at all, you are telling them that civil war and revolution is their only option.
I've seen quite a few posts saying that Pence finally stood up for democracy, and told Trump he wouldn't stop a fair election, and that there must be a flicker of morality in there somewhere.
And I strongly suspect that, rather than Pence suddenly developing a backbone, he looked at what would happen if he tried to tell more than half the country that having a majority wasn't enough, and that winning more than half of the electoral college wasn't enough, and decided that that was an abyss he did not want to fall in to.
*Sometimes, as in the UK, in a pretty rubbish way, but still.
Original post on Dreamwidth - there are comments there.