First-time, liberal candidates are flooding the Democratic primaries

A surge of liberal enthusiasm has intensified Democratic House primaries across the country, as factions within the party attempt to craft the lineup of candidates in their image.

According to an analysis of political donor networks, this year’s Democratic candidates are the most liberal in decades. Hundreds of newcomers registered to run, setting up primary scrums in competitive districts and eventual challenges to Republicans for rarely contested seats.

It’s still too early to know whether enough liberals will win enough primaries to pull the Democrats’ slate of general election candidates to the left, as Republicans did to the right in 2010.

Another unknown: whether the Democrats on the ballot in November can flip enough seats — about two dozen — to regain control of the House. The party has already tried to box out candidates it thinks cannot win in a general election, to the ire of liberals.

These charts use a measure known as the DIME score, an estimation of the ideological lean of a candidate based on his or her donors. The model was created by Stanford political science professor Adam Bonica.

“The basic assumption here is that if you’re liberal, you’re much more likely to give to liberal candidates,” Bonica said.

The scores track closely with DW-Nominate — a widely used measure of left-right lean based on voting record. But that score only works for legislators. DIME scores can estimate ideology for people who have never held office, too.

But, if donors act unusually — for instance, a race could gain national attention and attract a wider array of donors than is typical — the scores could seem off.

The data have updated with the information campaigns filed with the Federal Election Commission for the first quarter of 2018. We have excluded candidates with fewer than 20 donors who have given to other candidates because those scores are less reliable. (Explore House races and read more on how the score works below.)

A mirror image of 2010

“I think what we are seeing is not dissimilar from what we saw in 2010,” said Ken Spain, who was the communications director for the National Republican Congressional Committee during those elections.

Many Democrats who have raised money to run this year have never run before. As in 2010 — a banner year for Republicans — the political newcomers have emerged from the more extreme end of the party. Alternatively, Republicans have very few first-timers.

In the 2010 midterm year, the pattern was flipped: Many newcomer Republicans were more conservative and fewer first-time Democrats ran.

“Trump has clearly motivated the Democratic base to levels that we probably have not seen since 2006,” Spain said.

That year, Democrats capitalized on frustration with President George W. Bush by flipping 30 seats and taking back control of the House after 12 years out of power.

Liberals running in Trump territory

Some first-time candidates are running in deep-red districts — more than 40 percent of them in places that Trump won by double digits. The Democratic primary winner in those places would almost certainly face difficulty in the general election.

“People should still run because anything can happen,” said Diane May, a spokeswoman for Sen. Bernie Sanders’s group Our Revolution.

Spain also said to expect some surprises when Democrats, with “the wind at their backs,” are running in so many districts.

“The overwhelming majority of those candidates are unlikely to be successful,” he said. “But if you can catch an incumbent napping, there will be one or two opportunities where major upsets occur.”

What the score can show

In competitive primary races, the scores can help distinguish which candidates represent which parts of the party. This is especially helpful in districts where winning a primary virtually guarantees a seat in Congress because of the dominance of one party in the area.

That was the case in the hotly contested Illinois 3rd District, which Hillary Clinton won by 15 percentage points in 2016. Rep. Dan Lipinski, a conservative House Democrat, narrowly defeated Marie Newman, a liberal activist who earned the backing of Sanders and many liberal groups.

That difference between Lipinski and Newman appears in their DIME scores.

Lipinski, who had the backing of the antiabortion Susan B. Anthony List, is pulled much closer to the center of the DIME score spectrum, while Newman’s liberal donors place her more to the left.

“The congressperson that [Newman] ran against is not progressive,” said May, whose group backed Newman. “And if we’re really examining what it means to be a Democrat, likely not a Democrat either.”

Explore the ideology of House candidates

In the table below, explore the estimated ideology of candidates in House districts across the country.