End voter take all for the various States
This is up to the states, and therefore will never happen on its own, since no Blue state is going to voluntary give Red more power, and no Red state is going to voluntarily give Blue more power. This arms race is how we got into the winner-take-all mess in the first place.
The only hope is an inter-state pact that only takes effect after enough states have signed onto it that there’s no unfair advantage.
The National Popular Vote Interstate Compact ( NPVIC) is an agreement among a group of U.S. states and the District of…en.wikipedia.org
Enact into law something like the Wyoming Rule to even out how many people each Congressman represents
This requires increasing the number of congressman, though?
An equivalent change (which will never, ever fly) would be to give congressmen fractions of a vote based on population instead of whole numbers. :D