So, if this is true, what have the Democrats done to get your vote since 2016? Because Jill Stein took almost a mil and a half, and Clinton lost by less than that by far. So if this hypothesis is correct, they would have done something since to earn your vote. Also, the libertarian candidate took nearly 4.5 mil. Have the Republicans moved three times further towards the libertarian party as the Dems did towards the greens? Because I don't think that the evidence supports this hypothesis. If you still believe it, what evidence, if any, would convince you otherwise?

I submit that you can accomplish far more shifting by:

Getting your candidates into local elections
Engaging in coordinated contact campaigns to the elected party members of the party you had hoped to shift
Engaging in coordinated contact campaigns to the large money donors to the party you wish to shift

It's not simple, it's not sexy, it's not fast or rapidly gratifying. That's just how the world is. Any low hanging fruit along those lines has been plucked and sucked dry long since, and you'll have to put in the work if you want to change things.