As several have pointed out, fixing gerrymandering would be necessary--though this might be the only way to create the required social and political pressures to pull that off. Personally, I'd actually like to see district lines as something that must be voted on--so if a region decides that it makes the most sense for them to use community boundaries for setting their lines, they can.
I would definitely require the maps used by any region to set the districts for anything be freely & easily available to the public in their 'raw' form--and the methods used to set any boundaries on that map that aren't physical parts of the territory be both transparent and conform to a widely-accepted standard. That includes political boundaries. We had a couple states realizing that whoops we kiiiinda lost our border this century--didn't make much news or anything, because they decided to do the equivalent of a quiet-but-frantic search together instead of fight it out like...well...the last time that happened sometime in the 90s or so... (I wish I was kidding, but basically a lot of the boundaries are based off of old documents that are...not always where we think they got stored, or which when we check them are...not as exact as could be wished, to put it mildly, or don't say what we've been assuming they did for...well, this case? We're talking centuries of 'misremembering' the documents' contents...)
But a pure popular vote means that basically anybody outside of the megalopolises doesn't matter enough--they're as important to a person who wants to be POTUS as a state seen as 'in the bag' is now. Instant runoffs might fix that, some, but only if the third parties actually got their acts together--this could have been their election cycle.