Supporters of Turkish President Recep Tayyip Erdogan during a pro-government demonstration in Istanbul on July 19. (Alkis Konstantinidis/Reuters)

TURKISH PRESIDENT Recep Tayyip Erdogan has responded to a failed military coup with what amounts to a political coup of his own. Since last weekend, tens of thousands of Turks have been arrested or fired from their jobs: not just military officers involved in the rebellion but also teachers, university professors, judges and thousands of other civil servants. A state of emergency has been declared; hundreds of schools have been closed; dozens of journalists have had their credentials revoked. According to Turks monitoring the purge, those targeted include not just supporters of the exiled Islamic leader Mr. Erdogan blames for the coup, but also anyone suspected of not supporting his government, including members of minority groups and secular liberals.

Mr. Erdogan, who called the failed putsch a “gift from God,” is not just moving to further consolidate what already had become an authoritarian regime. He is also attempting to force the United States, Turkey’s NATO ally, to aid his crackdown — in particular by handing over the alleged mastermind of the coup, Pennsylvania-based cleric Fethullah Gulen. The Obama administration is rightly resisting — and it must continue to do so even if it means a breach in cooperating with Turkey against the Islamic State.

Mr. Gulen leads a peaceful, if secretive, Islamic movement that operates schools in Turkey, the United States and other parts of the world. For years, his followers in the Turkish police and judiciary were allied with Mr. Erdogan’s own Islamist party — ironically, the two combined to purge the Turkish military of officers suspected of coup-plotting. But the two leaders fell out in late 2013, when the government moved to close some Gulenist schools and prosecutors suspected of Gulenist sympathies brought major corruption cases against the government.

Mr. Erdogan has since carried out purges of the police, judiciary and press to eliminate Mr. Gulen’s followers, and it is not surprising he would blame the coup attempt on his rival. What he has not offered is evidence that a 75-year-old man confined to a remote compound in the Poconos somehow orchestrated a military uprising across Turkey. Remarkably, Mr. Erdogan’s foreign minister, Mevlut Cavusoglu, told The Post on Tuesday that there was no need for proof. “They should understand, they don’t need any evidence,” Mr. Cavusoglu said of the Obama administration.

Actually, they do. Though the United States has an extradition treaty with Turkey, Mr. Gulen cannot be arrested or returned to his homeland unless Turkey can convince the Justice Department, and federal courts, that he may be properly charged with a crime. (For the record, Mr. Gulen has denied any involvement in the coup.) In other words, he cannot be treated like Mr. Erdogan’s Turkey-based opponents and be swept up without due process.

President Obama apparently tried to explain this to Mr. Erdogan in a phone call Tuesday. According to spokesman Josh Earnest, Mr. Obama said that “the United States doesn’t support individuals who conspired to overthrow democratically elected governments” but also that “the United States follows the rule of law.” It won’t be surprising if Mr. Erdogan doesn’t accept that answer, or if he tries to use Turkey’s military relationship with the United States — including U.S. use of Incirlik Air Base for bombing Islamic State targets — as leverage. So be it: Mr. Erdogan needs to understand that the United States cannot be bullied into abetting his consolidation of a dictatorship.