As the 2018 primary season moved into high gear this week with contests in Indiana, North Carolina, Ohio and West Virginia, both wings of the Democratic Party have reason to celebrate. The progressive wing of the Democratic Party, most recently associated with the presidential candidacy of Senator Bernie Sanders, is providing a boost of activism and energy to the Democrats. For instance, take a look at the following graph. In a year where we are seeing a large increase in the total number of Democratic candidates we are also seeing a very large increase in the percentage of self-identified progressive Democrats running in primaries.

Compared to 2016 and 2014, the number of progressive candidates—many of them endorsed by political action groups that have sprung up in the wake of the 2016 presidential election—has increased sharply in all of the states that have had primaries so far, with the exception of West Virginia.

Another piece of good news for Democrats is that by and large these candidates are not engaging in a civil war inside the Democratic Party. In order to take control of the House of Representatives, Democrats need a net gain of 24 seats. If the newly energized progressive candidates were challenging Democrats in safe seats, their actions would probably not lose the seat for the Democrats but they could weaken the incumbent and prompt the need to put more resources into what was a safe district. Of even more concern was that progressives would challenge Democrats in Democratic-leaning districts on the grounds that they were insufficiently liberal. This kind of challenge could cost Democrats seats in a year when they should be gaining seats.

Instead of forming a circular firing squad and endangering Democratic incumbents, thus far progressive challengers have tended to run in districts where there are Republican incumbents or open seats where Republican incumbents have retired. Only eight progressive challengers have run against a sitting Democratic incumbent, compared to over sixty who have entered a primary for the opportunity to take on a Republican representative this fall. The following chart tells us a little more about where these progressives are running: in districts narrowly lost by Hillary Clinton.

Of course in primary politics, parties always have to worry about getting it wrong and ending up with a weak candidate in the general election. Often the misstep is nominating a candidate who is either too liberal or too conservative for the district depending on the party. The following table shows the outcomes of the Democratic congressional primaries in six states so far, based on their self-described ideology. A total of 117 non-incumbents ran as establishment or moderate and 30 percent of them won their races. This is probably good news for Democrats because so many of these contests are taking place in Republican-leaning districts where a more moderate Democrat stands a better chance. Another 99 non-incumbents ran as progressives and 18 percent won.

Table 1. Democratic Non-incumbent House Candidates Win Lose Adv. to Runoff Establishment 32

(29.9%) 65

(60.7%) 10

(9.3%) Moderate 3

(30%) 7

(70%) 0

(0%) Progressives 18

(18.2%) 69

(69.7%) 12

(12.1%)

Data covers 95 districts in six states (IL, IN, NC, OH, TX, WV), with 71 districts featuring more than one Democratic candidate. Row percentage sums may not equal 100% due to rounding. Candidates categorized as “Other” not included.

A good example is the race in Ohio’s 10th congressional district, currently held by Republican Michael Turner. This district is historically slightly Republican with a Cook Political Voting Index score of Republican +4. President Trump beat Hillary Clinton in the district by 7 percentage points. In the Democratic primary Theresa Gasper, the establishment candidate, beat two progressive candidates by large margins – she received 67 percent of the vote to a combined 33 percent of the vote for the other two. While the district is still a “likely” Republican district, Democrats seem to have chosen a candidate who is a better fit for the district.

However, there are other issues besides having an ideology that works in the state or district that make for a strong nominee. The race in Ohi

o’s 10district was downgraded earlier this spring because of unflattering headlines stemming from Congressman Turner’s ugly divorce . Another example comes out of one of the marquee races from this week’s primaries—the race to nominate a Democrat to succeed retiring Governor John Kasich (R-Ohio). In that race two progressives faced off: former congressman Dennis Kucinich and Richard Cordray, the former head of the Consumer Financial Protection Bureau. Each had the backing of one progressive wing of the Democratic Party: Kucinich was endorsed by Our Revolution , one of the political action groups that emerged after Senator Sanders’ presidential run, and Cordray was endorsed by Senator Elizabeth Warren . Senator Sanders himself stayed out of the race. But Kucinich was a weak candidate on other grounds, especially because of his confusing ties to Syria , and the voters overwhelmingly chose Cordray. So that’s both one win and one loss for progressives. In this case ideology is not the story.

There are many more primaries to come and these early trends may well be reversed. As in 2014 and 2016 we expect to learn a great deal about what is happening within the two very large tents we call American political parties. We will be adding to our data every week now that the primary season is in full swing and we hope it will inform our knowledge of the intra-party dynamics that are so critical to understanding American politics.

Elaine C. Kamarck is a Senior Fellow at the Brookings Institution and author of Primary Politics: Everything You Need to Know about How America Nominates Its Presidential Candidates. She is a member of the Democratic National Committee and a superdelegate to the Democratic convention.