During a conversation at the Center for American Progress on Thursday, presidential candidate* Hillary Clinton and House Minority Leader Nancy Pelosi (D-Calif.) started debating one of the most contentious issues in contemporary liberal politics: Which is the more progressive state, California or New York?

This is actually a very interesting question. The states are more similar than they might seem to the casual observer upon quick reflection: Dense areas of very Democratic votes with geographically separated Republican strongholds. Regional tensions. A decent amount of rural area. A reputation for passing progressive legislation. The answer to the question posed by Clinton and Pelosi, though, hinges a lot on what you mean by "progressive." So we pulled a bunch of possible metrics to determine the answer.

To cut to the chase: On the 23 metrics we surveyed, New York was more liberal on 13 -- a solid victory for the Empire State, to be sure. But half the debate is always more fun than the resolution, so here's how we did the math.

Voter registration

One of the best ways to figure out people's political beliefs is by looking at how they identify their party on their voter registration information.

Margin of Democratic versus Republican registration
New York: 26.15 points more Democratic
California: 14.99 points more Democratic
Advantage: New York

But each state also has a slew of minor parties that are probably a better measure of progressiveness/liberalness. There's the Working Families Party in New York and the Peace and Freedom Party in California, plus each has a Green Party.

Percent of all voters belonging to far-left parties
New York: 0.61 percent
California: 0.77 percent
Advantage: California

But there's another way to look at this: Which state has a wider margin of left-leaning versus right-leaning parties in total? New York's conservative party and California's libertarians deserve to be included in the mix. So:

Margin of liberal party membership over conservative party membership
New York: 25.44 points more liberal
California: 11.27 points more liberal
Advantage: New York

So, it's 2-1 New York after the first category.

(Sources: New York, California registrars.)

Congressional delegations

How do those voters actually vote? Both states have two Democratic senators, but their House delegations differ dramatically. The number of actual Democrats sent to the House is important, as it makes the state a more powerful force in the federal government. So:

Number of Democrats in the House delegation
New York: 21
California: 38
Advantage: California

Since we're looking at this by state, though, it's perhaps more important to consider how what percentage of the state's delegation are Democrats.

Percent of Democrats in the House delegation
New York: 77.78 percent
California: 73.58 percent
Advantage: New York

The National Journal ranks how liberal or conservative each state's House delegation is by evaluating the voting records of the individual members. It then develops statewide aggregates, which is particularly useful for our purposes.

Composite "liberal" score for the state's delegation
New York: 71.0
California: 67.6
Advantage: New York

But of its top 15 most liberal legislators, California has a clear advantage.
Average partisan voting index score
New York: 1
California: 6
Advantage: California

Presidential voting

Now let's look at how the two states have voted in presidential races.

Margin for Obama in 2012
New York: 28.18 points
California: 23.09 points
Advantage: New York

Raw vote differentiation is one thing. Geography is another. while the number of counties backing a president makes no difference in the ultimate vote total, it does suggest how geographically widespread that support might be.

Percent of counties carried by Obama in 2012
New York: 58.06 percent
California: 53.45 percent
Advantage: New York

Perhaps more importantly, we should look at where they've been -- and where they're going.

Average margin for Democratic presidential candidates since 1976
New York: 11.23 points
California: 3.94 points
Advantage: New York

In August, we looked at how state presidential voting in each state has compared to the national margin over time. We projected that trend out to 2020.

New-York California

Likely difference from national popular vote in 2020
New York: 21.7 points more Democratic
California: 24.78 points more Democratic
Advantage: California

State legislature

OK. That's all well and good. But what about how the states govern themselves? We'll start with the legislatures.

Margin of Democratic dominance in State Assembly
New York: 38.67 points
California: 37.5 points
Advantage: New York

For all of the state's progressive qualifications in other regards, New York's notoriously messy state Senate is about evenly split.

Margin of Democratic dominance in state Senate
New York: -1.69 points
California: 32.5 points
Advantage: California

Another factor to consider: Is the state's government single-party dominated -- allowing for passage of progressive bills -- or not?

Single-party control?
New York: No
California: Yes
Advantage: California

Which brings us to:

Governor

Both states currently have Democrats as governors. California Gov. Jerry Brown is probably objectively more progressive, so you might think California deserves a point there. But both states have also regularly elected Republicans to executive office -- including California electing Arnold Schwarzenegger. So we consider Brown and Arnie to be a wash.

Democratic wins in last 10 governor's races
New York: 7
California: 5
Advantage: New York

Margin of support for Democrats in last 10 races
New York: 11.78 percent
California: 0.04 percent
Advantage: New York

Which, for those keeping score at home, puts us at 10-6, New York.

Progressive policies

This is perhaps the heart of the matter. How progressive are New York and California when it comes to actually enacting progressive policies and issues? We identified five things on which to compare them.

Legalization of medical marijuana, year
New York: 2014
California: 1996
Advantage: California

Legalization of same-sex marriage, year
New York: 2011
California: 2013
Advantage: New York

(Why are we putting California at 2013 instead of 2008, when it was briefly legalized? Because of Proposition 8, in which voters banned gay marriage shortly thereafter.)

Percent saying abortion should be legal in all or most cases
New York: 61 percent
California: 65 percent
Advantage: California

(This is from Pew Research and reflects data on a regional basis. But California needs more points, right?)

Current minimum wage
New York: $8 an hour
California: $9 an hour
Advantage: California

Percentage of workers that belong to a union
New York: 24.4 percent
California: 16.4 percent
Advantage: New York

Other topics

Two other metrics came up as we were researching this article. Gallup does regular polling asking people to identify themselves on the political spectrum. People, including in New York and California, are more likely to say they're conservative than liberal. But:

Margin between those saying they're conservative versus liberal
New York: 4 points more conservative
California: 6.3 points more conservative
Advantage: New York

And one last comparison. Which state has a higher density of urban residents, which correlates with progressive attitudes? (Source.)

Percent urban
New York: 87.87 percent
California: 94.95 percent
Advantage: California

And that's it. Giving us a final score: New York, 13; California, 10. The more liberal state is New York.

If she really wanted to win this debate, maybe Pelosi should have backed that plan to split California into six states. Her state, "Silicon Valley," would win a progressiveness contest in a walk.


* You know why this asterisk is there.