It’s President Erdogan v. Pikachu. Whose side are we on? The main character in the animated “Pokémon” series — or someone in his image — was detected this week in a viral video of protesters fleeing the wrath of Turkish police. Protests across the country are swelling since the imprisonment, on sham allegations, of Mr. Erdogan’s most formidable foe, Ekrem Imamoglu, Istanbul’s mayor. Yet, President Trump calls the Turkish strongman a “good leader.” 

These columns have been supportive of Mr. Trump as he fought back against lawfare. Endless criminal prosecutions and civil lawsuits were attempted in an effort to end the political career of the Republican when he was out of power. So one would think that Mr. Trump would have a soft spot for Mr. Imamoglu. The mayor’s popularity rose as Erdoganomics nosedived, securing a landslide victory last week as leader of the opposition. 

Beyond the sagging economy, the public has soured on Mr. Erdogan’s increasingly autocratic hold on power. Turks are also pushing back against Islamic dictates enforced by Mr. Erdogan. Previous protest movements found no credible leadership. Now the opposition is widely united behind Mr. Imamoglu and his Republican People’s Party, the CHP. Feeling the heat, Mr. Erdogan proceeded to incarcerate his most formidable rival.  

Even as street protests swell, though, Mr. Erdogan seems to trust his violent enforcers to end it soon. He recently made peace with a former Kurdish political enemy, Abdullah Ocalan, and now he is hoping to marshal enough parliamentary support to change the Turkish constitution. He’s done it once before, moving the center of power to the presidency from the prime ministry. Now he plans to end term limits and get reelected in 2028, if not before. 

We hope the idea of a lifetime ruler is not the reason our president is praising Mr. Erdogan. Meeting ambassadorial nominees on Tuesday, Bloomberg reports, Mr. Trump said of Turkey, “good place, good leader, too.” That was two days after Mr. Imamoglu was thrown into a dungeon. Mr. Trump is often accused of harboring admiration for leaders who rule with an iron fist. Mr. Erdogan, though, is more than that. 

The Turk’s moves against the political opposition, the press, the judicial system, and the security apparatus are worrisome enough. Yet that is for the Turkish people to sort out. It’s the Ankara pasha’s dream of recreating the Ottoman Empire that worries us. From the Balkans to the Arabian deserts and, especially now Syria, Mr. Erdogan’s regional ambition spreads far beyond the Bosporus. His allies in that pursuit are, alas, far from America-friendly. 

Mr. Erdogan’s Turkey has cultivated Mideast Islamists. While Syria’s new leader, Ahmad al-Sharaa, has transformed into a suit’n’tie politician, his roots in Al Qaeda are occasionally showing. Mr. Sharaa’s Turkish patron won’t — or can’t — restrain Syria’s retreat into Islamo-fascism. Mr. Erdogan has long hosted Hamas leaders. He constantly whips up anti-Israel, antisemitic sentiment at home and across the region. Hatred of us Yanks is growing too.

Since the Cold War, Turkey has been a valued American ally. Its military is the second-largest in the North Atlantic Treaty. It’s a bridge between Europe and Asia. Yet, under Mr. Erdogan it’s increasingly difficult to tell if Ankara is a friend or foe. The deeper Turkey grows as an Islamist dictatorship, the less that “good leader” can be trusted. America might seek a more reliable ally, like the one the man in the Pikachu suit is supporting while fleeing police thugs.