AMNA NAWAZ: We turn now to our series "On Democracy," where we hear a range of perspectives on how government should function, what's led to this moment in American history, and where the country goes next.

With fewer than 100 days to go until the midterm elections, high-profile battles over redistricting have become a fixture in political headlines.

A number of Republican-led states under pressure from President Trump have redrawn their congressional maps to gain an election edge.

Some Democratic-led states have followed suit.

Those battles have already this year led to the elimination of majority-Black districts in Louisiana, Alabama, and Tennessee.

One group of scholars is sounding the alarm on the consequences of gerrymandering; 500 of the nation's top democracy, voting rights, and legal experts have signed an open letter to Congress urging lawmakers to consider one solution, proportional representation.

These scholars argue that single-member districts are -- quote -- "failing to deliver fair and representative outcomes" and are the result of outdated electoral rules that worsen gerrymandering.

A proportional system, they say, is a practical remedy.

Here with us to unpack this is one of the signatories.

That's Pamela Karlan, a law professor from Stanford University.

Pam, welcome to the show.

Thanks for joining us.

PAMELA KARLAN, Stanford University: Thanks for having me.

AMNA NAWAZ: So let's just start with why you decided to sign on to this letter and why now.

PAMELA KARLAN: Well, our system of electing people to Congress is broken.

Over the last several years, what we have seen is the Supreme Court has given a total green light to gerrymandering, partisan gerrymandering, and it's gutted the Voting Rights Act.

And the upshot of this is that instead of voters being able to elect the candidates of their choice, politicians are picking the voters of their choice.

And that's not healthy for a democracy.

AMNA NAWAZ: There was a similar letter that went out four years ago that had some 200 backers for it.

The fact that you're now up to 500 people arguing for this system, does that tell us something about consensus around this or this particular moment?

PAMELA KARLAN: Well, I think it does.

I mean, one of the things that we have seen over the last year-and-a-half is that states used to just redraw their congressional districts after the census came out, and now they're redrawing them again and again in an effort to squeeze out the last bit of partisan advantage.

And, as I said, nobody can look at that and think that that's a good system.

AMNA NAWAZ: So you argue in the letter that gerrymandering's gone too far, and that, in your words, the way to end redistricting wars is to make redistricting matter far less.

So just explain for us how proportional representation would do that.

PAMELA KARLAN: Well, instead of electing members of Congress from single-member districts, so we have 435 districts now, instead, what states that elect multiple members would do is, they would create districts that elect more than one member, and in which who gets elected depends on the proportion of votes that each party gets.

So, for example, in a state like Louisiana, which has six congressional seats, you might have two districts, each of which elect three people.

And what that would do is, it would enable numerical minorities to elect some candidates of their choice.

So it wouldn't be as winner-take-all as the system now is.

AMNA NAWAZ: Pam, even as the system could seek to solve one problem, could it create new ones?

I mean, one of the chief frustrations we hear from voters is gridlock within the systems.

Could a proportional system mean more parties or third independent parties are now empowered, they have to work towards coalitions?

Does it potentially create more gridlock?

PAMELA KARLAN: I don't think it's likely in the American system, because we're not a parliamentary system.

We are a presidential system.

And even if we were electing people from multiple districts, most of those districts would have three or four representatives, and that would mean that people would still have an incentive to vote for one of the major parties, as long as they're actually satisfied with what the major parties are doing.

AMNA NAWAZ: Just for some context here, we know the U.S.

is somewhat unique, in that the majority of nations around the world that have elected representation use proportional representation or mixed systems in some way to elect their legislators, or a little over 60 percent of those countries.

Why hasn't proportional representation been seriously considered in the U.S.

before?

PAMELA KARLAN: Well, one thing is that our system for electing members of Congress has been fixed since 1842.

And there's actually a really interesting speech that one of the senators gave in 1867, and he said, if we had known about proportional representation at the time, we might have gone for proportional representation, rather than districting.

Once you have a system in place, especially in a country like the United States, it's very sticky, because the members of Congress, they know they can get elected from single-member districts, and they don't know necessarily what would happen if we had a proportional system.

And so it's hard unless there actually turns out to be a political movement behind it to change the way elections are conducted.

AMNA NAWAZ: Well, that leads to my next question, which -- how realistic is it to implement this kind of system right now, especially given that the people who are navigating the system and benefiting from it would be loath to try to change that system at the same time?

How do you see that?

PAMELA KARLAN: In the short run, it's not going to change.

I mean, you really have to build a political movement behind this.

And part of what I hope we're going to start doing is having a real discussion about why our current system of electing members of Congress just doesn't work anymore.

And it's creating a system in which, although Congress is divided between the Democratic and Republican Parties, individual states don't have representation that's fair to people on both sides of the aisle in those states.

AMNA NAWAZ: If the system doesn't change, if there's no serious election reform, what do you see happening in the years ahead?

PAMELA KARLAN: Well, what I see happening is people becoming increasingly disillusioned with the system, people believing less and less that our democracy works, and that's not a healthy world in which to live.

AMNA NAWAZ: Pamela Karlan, law professor from Stanford University, thank you so much for your time.

Really appreciate it.

PAMELA KARLAN: Thanks for having me.