That has to happen at the state level, as they control how the elections are conducted.
Something I try to drum up in these sorts of threads is that your state and local elections can be far more important to pushing progressive policy than federal elections. Most of the work for high speed rail, for example, has to be taken up by state government. The federal government might offer some funding, but they only hold that out there for states to choose to take or not. Same with bicycle lanes, housing, or diverting police funding into more comprehensive solutions. That’s all state and local government.
Voting for Democrats at the federal level is merely to keep some of that funding sitting out there, and to not actively block progress otherwise. That’s it. That’s what voting them into the White House and Congress is for. The rest needs to be done in your local community.