Democratic presidential candidate Vermont Sen. Bernie Sanders is under fire for his characterization of some progressive groups — including Planned Parenthood — as “establishment,” but many of his supporters agree.

During an interview with Rachel Maddow on MSNBC Tuesday evening, Sanders said his campaign is “taking on not only Wall Street and the economic establishment, we’re taking on the political establishment.”

Asked why groups like the Human Rights Campaign and Planned Parenthood have endorsed former Secretary of State Hillary Clinton instead of him, Sanders said that he has “friends and supporters” in those groups, “but you know what, Hillary Clinton has been around there for a very, very long time and some of these groups are, in fact, part of the establishment.”

Clinton responded on Twitter:

Planned Parenthood has given Sanders’ voting record a score of 100 percent. The organization faced backlash for its endorsement of Clinton from many Sanders supporters who noted that the daughter of Planned Parenthood President and CEO Cecile Richards works for the Clinton campaign.

HOOKSETT, NH - JANUARY 10: Cecile Richards, Planned Parenthood Action Fund President, introdces Democratic Presidential candidate Hillary Clinton at an endorsement event at Southern New Hampshire University January 10, 2016 in Hooksett, New Hampshire. This marks the first time the organization has ever given an endorsement in a primary race. (Photo by Darren McCollester/Getty Images)

Cecile Richards, Planned Parenthood Action Fund President, introduces Democratic presidential candidate Hillary Clinton at an endorsement event at Southern New Hampshire University Jan. 10 in Hooksett, New Hampshire, marking the first time the organization has ever given an endorsement in a primary race. (Darren McCollester/Getty Images)

A spokesperson for Planned Parenthood did not immediately return TheBlaze’s request for comment. The organization did respond to Sanders’ comment on Twitter:

Sanders’ supporters defended his remarks on Twitter.

Some Twitter users defended Planned Parenthood.

The Human Rights Campaign also defended their endorsement of Clinton on Twitter: