House Speaker Nancy Pelosi (D-Calif.) cracked down on her caucus in a closed-door meeting Wednesday, demanding that members stop attacking one another publicly. It was a continuation of tensions between Pelosi and the focus of those comments, a group of four Democratic freshman representatives — Alexandria Ocasio-Cortez (N.Y.), Rashida Tlaib (Mich.), Ilhan Omar (Minn.) and Ayanna Pressley (Mass.) — who’ve been advocating more progressive policies among their peers.

This tension between Pelosi and the four freshmen has grown over the past week, with the speaker disparaging them in an interview with Maureen Dowd of the New York Times as having “their public whatever and their Twitter world” but not being able to translate that public popularity into votes in the House. In an interview with The Washington Post, Ocasio-Cortez called Pelosi’s behavior “disrespectful.”

Ocasio-Cortez noted that the four members targeted by Pelosi are women of color, though she later clarified that she wasn’t suggesting that Pelosi was racist. The tension, though, may in fact stem in part from demographics: age.

“If the left doesn’t think I’m left enough, so be it,” Pelosi told Dowd, getting at one of the key tensions between herself and the four freshmen. “As I say to these people, come to my basement. I have these signs about single-payer from 30 years ago.”

There’s a distinctive part of the debate within the Democratic Party that centers on younger Democrats pushing for faster change on policies that older Democratic elected officials have spent years trying to advance incrementally, given the political environment. Climate change, health care, changes to the criminal justice system: Democratic leaders, including Pelosi, have been pushing on these issues for years against Republican congresses and with a more moderate Democratic base. The party’s base has moved to the left in recent years, however, and younger Democrats, in particular, are eager for a shift away from strategies that are seen as moderated or incremental.

Pelosi’s right, though. Her voting record, according to an analysis from VoteView, has consistently been on the more liberal end of the party’s members in the House.

Those data use a metric called DW-NOMINATE, which assumes a consistent ideological standing over the course of a politician’s career. (The actual scores don’t matter much, just that the lower part of the graph is more liberal.) Changes in the caucus’s ideology reflect members leaving and joining the group. Last year’s Democratic wave election brought in a number of more-moderate members from Republican-leaning districts, shifting the average ideology.

This metric offers an incomplete picture of Pelosi’s tenure. VoteView also compiles a Nokken-Poole estimate, which looks at how members vote within a particular Congress. Here, we see more movement in Pelosi’s voting record.

The Democratic caucus has gotten a bit more liberal on average. Pelosi has gotten a bit less liberal. The result? She’s moved closer to the caucus average.

That shift has been pronounced since she became the party’s leader in the House. The pull can work two ways: She has a responsibility to give cover to more moderate Democrats to protect their electoral chances, meaning that she’ll advocate and vote for more moderate legislation. But she can also advocate more progressive legislation that pushes her members to move in a more liberal direction.

The DW-NOMINATE scores for the four new members are preliminary, because they are new to Congress. The raw data used to compile the averages over time has all four as relatively moderate in their votes (dark green marker). Data released by VoteView in June, though, shows the average score for the four freshmen as significantly more liberal than most Democrats (light green marker) — and, in fact, more liberal than the most liberal 10 percent of Democrats in the House.

(This is slightly apples-and-oranges-y, picking out their four scores while not updating the scores for the other 231 Democrats, but it still serves to illustrate the point.)

If we compare DW-NOMINATE scores with the Cook Political Report’s partisan voting index, a look at the partisan lean of House districts based on presidential election voting, we see that Pelosi’s voting history and district are both more liberal than most of the rest of her caucus.

The light-green outlined markers for the four freshmen indicate their June scores — with Ocasio-Cortez landing as one of the most moderate members of the caucus. The VoteView team explains that this is because “there have been relatively few roll calls taken that divide the left wing of the Democratic caucus from the moderates,” meaning that “there have been few opportunities for freshman liberals to show their stripes.”

What’s remarkable on this chart are the scores for Tlaib, Pressley and Omar, all of whom have noticeably liberal voting records, even relative to the lean of their districts. They can’t compare, though, with Rep. Lauren Underwood (D-Ill.), who represents a Republican-leaning district (after defeating a Republican incumbent last year) and has one of the most liberal voting records. Underwood is an outlier in her caucus.

But Underwood doesn’t have the same profile as Ocasio-Cortez or Omar. What’s more, she voted with Pelosi on a compromise immigration bill last month, while the four freshmen did not. That bill was the specific target of Pelosi’s comments about the four not being able to get votes, telling Dowd that “they didn’t have any following. They’re four people and that’s how many votes they got.”

For now. One thing Pelosi wants to avoid as she tries to position her caucus where she thinks it will have the most success is Ocasio-Cortez, Pressley, Omar and Tlaib managing to persuade other Democrats to join them in crusades for more progressive legislation. Hence the call Wednesday for a unified front.