August 20, JDN 2457986

After humiliating defeats in the last election, the Democratic Party is now debating how to recover and win future elections. One proposal that has been particularly hotly contested is over whether to include candidates who agree with the Democratic Party on most things, but still oppose abortion.

This would almost certainly improve the chances of winning seats in Congress, particularly in the South. But many have argued that this is a bridge too far, it amounts to compromising on fundamental principles, and the sort of DINO (Democrat-In-Name-Only) we’d end up with are no better than no Democrats at all.

I consider this view deeply misguided; indeed, I think it’s a good portion of the reason why we got so close to winning the culture wars and yet suddenly there are literal Nazis marching in the streets. Insisting upon ideological purity on every issue is a fantastic way to amplify the backlash against you and ensure that you will always lose.

To show why, I offer you a simple formal model. Let’s make it as abstract as possible, and say there are five different issues, A, B, C, D, and E, and on each of them you can either choose Yes or No.

Furthermore, let’s suppose that on every single issue, the opinion of a 60% majority is “Yes”. If you are a political party that wants to support “Yes” on every issue, which of these options should you choose:
Option 1: Only run candidates who support “Yes” on every single issue

Option 2: Only run candidates who support “Yes” on at least 4 out of 5 issues

Option 3: Only run candidates who support “Yes” on at least 3 out of 5 issues

For now, let’s assume that people’s beliefs within a district are very strongly correlated (people believe what their friends, family, colleagues, and neighbors believe). Then assume that the beliefs of a given district are independently and identically distributed (each person essentially flips a weighted coin to decide their belief on each issue). These are of course wildly oversimplified, but they keep the problem simple, and I can relax them a little in a moment.

Suppose there are 100 districts up for grabs (like, say, the US Senate). Then there will be:

(0.6)^5*100 = 8 districts that support “Yes” on every single issue.

5*(0.6)^4*(0.4)*100 = 26 districts that support “Yes” on 4 out of 5 issues.

10*(0.6)^3*(0.4)^2*100 = 34 districts that support “Yes” on 3 out of 5 issues.

10*(0.6)^2*(0.4)^3*100 = 23 districts that support “Yes” on 2 out of 5 issues.

5*(0.6)^1*(0.4)^4*100 = 8 districts that support “Yes” on 1 out of 5 issues.

(0.4)^5*100 = 1 district that doesn’t support “Yes” on any issues.

The ideological purists want us to choose option 1, so let’s start with that. If you only run candidates who support “Yes” on every single issue, you will win only eight districts. Your party will lose 92 out of 100 seats. You will become a minor, irrelevant party of purists with no actual power—despite the fact that the majority of the population agrees with you on any given issue.

If you choose option 2, and run candidates who differ at most by one issue, you will still lose, but not by nearly as much. You’ll claim a total of 34 seats. That might at least be enough to win some votes or drive some committees.

If you want a majority, you need to go with option 3, and run candidates who agree on at least 3 out of 5 issues. Only then will you win 68 seats and be able to drive legislative outcomes.

But wait! you may be thinking. You only won in that case by including people who don’t agree with your core platform; so what use is it to win the seats? You could win every seat by including every possible candidate, and then accomplish absolutely nothing!

Yet notice that even under option 3, you’re still only including people who agree with the majority of your platform. You aren’t including absolutely everyone. Indeed, once you parse out all the combinations, it becomes clear that by running these candidates, you will win the vote on almost every issue.

8 of your candidates are A1, B1, C1, D1, E1, perfect partisans; they’ll support you every time.

6 of your candidates are A1, B1, C1, D1, E0, disagreeing only on issue E.

5 of your candidates are A1, B1, C1, D0, E1, disagreeing only on issue D.

5 of your candidates are A1, B1, C0, D1, E1, disagreeing only on issue C.

5 of your candidates are A1, B0, C1, D1, E1, disagreeing only on issue B.

5 of your candidates are A0, B1, C1, D1, E1, disagreeing only on issue A.

4 of your candidates are A1, B1, C1, D0, E0, disagreeing on issues D and E.

4 of your candidates are A0, B1, C1, D0, E0, disagreeing on issues E and A.

4 of your candidates are A0, B0, C1, D1, E1, disagreeing on issues B and A.

4 of your candidates are A1, B0, C1, D1, E0, disagreeing on issues E and B.

3 of your candidates are A1, B1, C0, D0, E1, disagreeing on issues D and C.

3 of your candidates are A1, B0, C0, D1, E1, disagreeing on issues C and B.

3 of your candidates are A0, B1, C1, D0, E1, disagreeing on issues D and A.

3 of your candidates are A0, B1, C0, D1, E1, disagreeing on issues C and A.

3 of your candidates are A1, B0, C1, D0, E1, disagreeing on issues D and B.

3 of your candidates are A1, B1, C0, D1, E0, disagreeing on issues C and E.

I took the liberty of rounding up or down as needed to make the numbers add up to 68. I biased toward rounding up on issue E, to concentrate all the dissent on one particular issue. This is sort of a worst-case scenario.

Since 60% of the population also agrees with you, the opposing parties couldn’t have only chosen pure partisans; they had to cast some kind of big tent as well. So I’m going to assume that the opposing candidates look like this:

8 of their candidates are A1, B0, C0, D0, E0, agreeing with you only on issue A.

8 of their candidates are A0, B1, C0, D0, E0, agreeing with you only on issue B.

8 of their candidates are A0, B0, C1, D0, E0, agreeing with you only on issue C.

8 of their candidates are A0, B0, C0, D1, E0, agreeing with you only on issue D.

This is actually very conservative; despite the fact that there should be only 9 districts that disagree with you on 4 or more issues, they somehow managed to win 32 districts with such candidates. Let’s say it was gerrymandering or something.

Now, let’s take a look at the voting results, shall we?

A vote for “Yes” on issue A will have 8 + 6 + 3*5 + 2*4 + 4*3 + 8 = 57 votes.

A vote for “Yes” on issue B will have 8 + 6 + 3*5 + 2*4 + 4*3 + 8 = 57 votes.

A vote for “Yes” on issue C will have 8 + 6 + 3*5 + 4*4 + 2*3 + 8 = 59 votes.

A vote for “Yes” on issue D will have 8 + 6 + 3*5 + 3*4 + 3*3 + 8 = 58 votes.

A vote for “Yes” on issue E will have 8 + 0 + 4*5 + 1*4 + 5*3 = 47

Final results? You win on issues A, B, C, and D, and lose very narrowly on issue E. Even if the other party somehow managed to maintain total ideological compliance and you couldn’t get a single vote from them, you’d still win on issue C and tie on issue D. If on the other hand your party can convince just 4 of your own anti-E candidates to vote in favor of E for the good of the party, you can win on E as well.

Of course, in all of the above I assumed that districts are homogeneous and independently and identically distributed. Neither of those things are true.
The homogeneity assumption actually turns out to be pretty innocuous; if each district elects a candidate by plurality vote from two major parties, the Median Voter Theorem applies and the result is as if there were a single representative median voter making the decision.

The independence assumption is not innocuous, however. In reality, there will be strong correlations between the views of different people in different districts, and strong correlations across issues among individual voters. It is in fact quite likely that people who believe A1, B1, C1, D1 are more likely to believe E1 than people who believe A0, B0, C0, D0.

Given that, all the numbers above would shift, in the following way: There would be a larger proportion of pure partisans, and a smaller proportion of moderates with totally mixed views.

Does this undermine the argument? Not really. You need an awful lot of pure partisanship to make that a viable electoral strategy. I won’t go through all the cases again because it’s a mess, but let’s just look at those voting numbers again.

Suppose that instead of it being an even 60% regardless of your other beliefs, your probability of a “Yes” belief on a given issue is 80% if the majority of your previous beliefs are “Yes”, and a probability of 40% if the majority of your previous beliefs are “No”.

Then out of 100 districts:

(0.6)^3(0.8)^2*100 = 14 will be A1, B1, C1, D1, E1 partisans.

Fourteen. Better than eight, I suppose; but not much.

Okay, let’s try even stronger partisan loyalty. Suppose that your belief on A is randomly chosen with 60% probability, but every belief thereafter is 90% “Yes” if you are A1 and 30% “Yes” if you are A0.

Then out of 100 districts:

(0.6)(0.9)^4*100 = 39 will be A1, B1, C1, D1, E1 partisans.

You will still not be able to win a majority of seats using only hardcore partisans.

Of course, you could assume even higher partisanship rates, but then it really wasn’t fair to assume that there are only five issues to choose. Even with 95% partisanship on each issue, if there are 20 issues:
(0.95)^20*100 = 36

The moral of the story is that if there is any heterogeneity across districts at all, any meaningful deviation from the party lines, you will only be able to reliably win a majority of the legislature if you cast a big tent. Even if the vast majority of people agree with you on any given issue, odds are that the vast majority of people don’t agree with you on everything.

Moreover, you are not sacrificing your principles by accepting these candidates, as you are still only accepting people who mostly agree with you into your party. Furthermore, you will still win votes on most issues—even those you felt like you were compromising on.

I therefore hope the Democratic Party makes the right choice and allows anti-abortion candidates into the party. It’s our best chance of actually winning a majority and driving the legislative agenda, including the legislative agenda on abortion.