Six Democratic senators want to know if law clerks participating in a conservative organization’s training program violated the judicial codes of conduct.

The Heritage Foundation, which held the training program in February, has advocated for “repealing reproductive rights; dismantling affirmative action policies; limiting voting rights; and restrictive immigration policies,” the Judiciary Committee members said in a letter to James Duff, the director of the Administrative Office of the U.S. Courts.

The organization has touted its role in helping President Donald Trump select nominees to the U.S. Supreme Court.

The criticism echoes Democrat attacks on the Federalist Society, an organization of conservatives and liberals that also helped Trump select nominees.

The senators led by the top Judiciary Committee Democrat, Dianne Feinstein of California, “seriously question” Heritage’s decision to hold the training program, they said.

The anonymously-funded program originally made participants pledge their secrecy and promise not to use their training for purposes contrary to the interests of the Heritage Foundation, the senators said.

It also held a session about immigration law on the same day that the foundation released a report concerning its immigration agenda, the letter said.

The senators asked whether any current or future judge or judicial employee asked the office for advice about attending that program, and what conclusion the office reached if they did.

The letter cited guidance that the office issued after the program, which listed situations in which attending certain events could violate judicial codes of conduct.

Concerns are raised when the event sponsor engages in contentious debates over public policy and the program is funded by unknown sources, according to that guidance.

Feinstein was joined by Sens. Sheldon Whitehouse of Rhode Island, Patrick Leahy of Vermont, Dick Durbin of Illinois, Richard Blumenthal of Connecticut, and Mazie Hirono of Hawaii.

The Heritage Foundation didn’t immediately respond to a request for comment.