WASHINGTON — Rep. John Shimkus, R-Ill., said “pull my name off the ‘I support Donald Trump list’” after the president abandoned U.S.-allied Kurds, a move he called “despicable.”

“I’m heartbroken by what we are enabling Turkey to do in Syria,” Shimkus said in a statement released Thursday, expanding on an interview he gave to KMOX radio host Mark Reardon on Wednesday.

Trump’s campaign made Shimkus an Illinois honorary co-chair. He said in his statement he asked “my name be removed from his campaign’s official list of supporters,” making him the highest-profile Republican in the House to break with the president.

While Trump punishes his critics — dealing with Republicans as harshly as Democrats — Shimkus is immune from Trump’s wrath because he announced in August he will not seek another term in 2020. When he leaves Capitol Hill, Shimkus will have served 24 years.

Shimkus, the senior Illinois House GOP member, is a respected conservative who represents a district anchored in southern Illinois. A West Point graduate, Shimkus lives in Collinsville, about 15 minutes from downtown St. Louis.

Asked by the Chicago Sun-Times for reaction to the Shimkus split, a Trump campaign spokesman declined comment.

Turkey bombed Kurdish targets in Syria after Trump announced Sunday he was removing U.S. troops who were allied with Kurds, clearing the way for the Turkish attack.

“I’m heartbroken,” Shimkus told KMOX. “In fact, I called my chief of staff in D.C. I said pull my name off the ‘I support Donald Trump list.’ I mean, this was just, we have just stabbed our allies in the back.”

“… This has just shocked, embarrassed and angered me.” Shimkus added, “It’s terrible. It’s despicable. I don’t have enough words to mention it. I am embarrassed by it and I am saddened for the Kurdish people.”

Shimkus had more to say in his Thursday statement. “I’m heartbroken by what we are enabling Turkey to do in Syria. The Kurdish people are not a major global power, but they have been friends to the United States for decades. They’re not asking for asylum or refuge in our country because they’re fighting for a secure, peaceful space in the land they call home. But long ago fate ordained that their fight, and their values, would align with our own military campaigns in that part of the world.

“As a result, next to Israel, the Kurds have become America’s most loyal allies from the Mediterranean Sea to the Sea of Japan through decades of conflicts. They’ve fought our battles in Syria and Iraq so that countless American sons and daughters didn’t have to. I’m angry and embarrassed. While my votes will continue to support the president’s domestic policy agenda, because of this terrible foreign policy decision, I asked that my name be removed from his campaign’s official list of supporters.”

Shimkus had not been an outspoken Trump critic until now. The first crack seems to have started after a whistleblower said Trump tried to pressure Ukraine President Volodymyr Zelensky to investigate his political rival, former Vice President Joe Biden, triggering the Democratic-led impeachment inquiry.

Shimkus has been to Ukraine twice this year, in April as an election monitor and last week. In a column posted Tuesday on Medium.com, Shimkus wrote, “I also urge restraint to those who would drag” Ukraine and Zelensky “into the scorched-earth politics of personal destruction practiced here at home these days. Ukraine is caught in a very real war against Russia, and they need the encouragement and reassurance of the United States’ friendship and support.”

Recently I asked Shimkus, 61, about his decision to retire at the end of this term.

He noted he’s been on the ballot every two years going back to 1988 in local and congressional races.

Said Shimkus, “I’m tired, and I just want to go home.”