ASSOCIATED PRESS Democratic presidential candidate Julián Castro arrives at a meeting with Iowa State University students in May. The former housing secretary was the first 2020 candidate to commit to paying campaign staff $15 an hour.

The job remains unglamorous, the tasks mostly thankless, but one thing is different about interns on the 2020 presidential campaign trail: Many of them can expect to be paid.

On Wednesday, at least six Democratic presidential campaigns confirmed they would offer paid internships, in response to a new pledge unveiled by the advocacy group Pay Our Interns.

The group has approached every confirmed presidential candidate and says Sens. Bernie Sanders (I-Vt.) and Cory Booker (D-N.J.) were the first to sign the pledge. Spokespeople for both senators confirmed that their campaigns are already paying interns.

Separately, spokespeople for Washington Gov. Jay Inslee, Rep. Tim Ryan of Ohio and Pete Buttigieg, mayor of South Bend, Indiana, and told HuffPost the candidates have signed the pledge or plan to do so. A spokesman for Sen. Elizabeth Warren said her campaign’s internship program will be paid once it launches, and spokesmen for Buttigieg and former Rep. Beto O’Rourke (D-Texas) said their campaigns plan to pay interns $15 an hour once interns are hired.

Former Housing Secretary Julián Castro committed in January to paying all campaign staff at least $15 an hour, a promise that his campaign said extends to interns.

The rolling count is a sign of rapidly changing expectations around political internships and whether they should be compensated.

Just two years ago, members of Congress who paid interns were a rarity, and major partyorganizations like the Democratic National Committee and the Democratic Congressional Campaign Committee required interns to work for free. Today, owing to groups like Pay Our Interns and to interns’ own advocacy, all three institutions, plus a growing list of political nonprofits around the capital, have money set aside to pay interns a summer stipend or hourly wage.

Paid internships can make a huge difference in terms of who has the ability to enter politics. As they agitated for future intern classes to be paid, interns at the DCCC wrote an open letter to then-chair Rep. Ben Ray Luján (D-N.M.) saying their unpaid status made it nearly impossible to recruit applicants from low-income and marginalized backgrounds.

“Unpaid internships favor only those who can afford [them] and they roll back diversity and inclusion efforts,” said Guillermo Creamer Jr., co-founder of Pay Our Interns.

After the DNC began paying its interns, the proportion who were people of color leaped from 18 percent to 42 percent.

In the 2018 midterms, Pay Our Interns counted at least a dozen congressional races that offered paid internships.

“That’s more than usual. We think the usual is zero,” said Carlos Mark Vera, another co-founder of Pay Our Interns. That number included even some races in which the candidates had raised only a few hundred thousand dollars. “So we want to know, what’s the excuse for Senate campaigns running multimillion-dollar races?”

For Sanders, the first to sign the pledge, paying interns is a longstanding practice. Only one-third of Senate Democrats chose to pay interns before Congress set money aside so that all offices would do so; Sanders’ office also paid interns during that earlier period.

Sanders likewise paid interns on his 2016 presidential campaign, while Hillary Clinton, his primary rival for the Democratic nomination that year, relied for a time on established political professionals taking unpaid fellowships.

“Bernie believes that no one should be locked out of getting an internship because their family can’t afford to cover their expenses,” a spokeswoman for the Sanders campaign said. “We appreciate the work our interns do and we’re proud to pay them for that work.”

This post is being updated as more campaigns respond.