Here are the current results of Alaska Measure 2 (2026), designed to repeal Alaska's ranked-choice voting. You can see that "Yes" votes are from predominantly Republican areas and "No" ones are from predominantly Democratic ones (note: Alaska is "flipped" from pretty much everywhere else in the US, where its largest city, Anchorage, is the state's Republican stronghold, while rural areas tend to be more Democratic).

Likewise, if you look at the National Popular Vote Interstate Compact, you'll see that it's predominantly Democratic states that have signed themselves into it. This is still first-past-the-post, but that's still meaningful progressive reform when the current situation is the Electoral College – FPTP 50 times amalgamated into one final FPTP vote.

Likewise, if you look at this article, you'll see the states exploring ranked-choice are mostly Democratic ones.

Voting is largely up to the states, so you'll want to look at the state level, not the federal. It's pretty obvious that Democratic voters are the ones hankering for things like ranked-choice voting, and thus it's inherently more likely that a Democratic-led government will implement voting reform than the Republican Party whose constituents actively oppose such reform.