Philip Guston is no longer here to defend himself — but his fellow artists are, and they are angry.

In an open letter published Wednesday in The Brooklyn Rail, nearly 100 artists, curators, dealers and writers forcefully condemned the decision last week by the National Gallery of Art in Washington and three other major museums to pull the plug on the largest retrospective in 15 years of one of America’s most influential postwar painters.

The show, after years of preparation, will be delayed until 2024. The stated reason is to let the institutions rethink their presentation of Guston’s later figurative paintings, which feature men in hoods reminiscent of Ku Klux Klan members, and which, a National Gallery spokesperson said, risked being “misinterpreted” today.

In the open letter, the artists, “shocked and disappointed,” accuse the museums — the National Gallery, Tate Modern in London, the Museum of Fine Arts, Boston, and the Museum of Fine Arts, Houston — both of betraying Guston’s art and of patronizing the public they are supposed to serve.

The postponement, they write, is an admission of the museums’ “longstanding failure to have educated, integrated, and prepared themselves to meet the challenge of the renewed pressure for racial justice that has developed over the past five years.” They demand that the Guston exhibition take place as scheduled, and that the museums “do the necessary work to present this art in all its depth and complexity.”