ISTANBUL — On the single worst day in the collapse of the Turkish lira, President Recep Tayyip Erdogan arrived late in the evening in a small town, stepped up on the runner of his car, tapped the microphone and delivered, impromptu, one of his most memorable speeches — an appeal to national and religious pride in the face of foreign aggression.

“They are now having various campaigns,” he said, referring to the financial sanctions imposed by the United States against Turkey this month. “You do not lend an ear to those. Don’t forget, they have the dollar, but we have our people, our Allah.”

Since his re-election in June to a newly powerful presidency, Mr. Erdogan has become, more than ever, the dominant government communicator to Turkey’s 81 million people. After 15 years in power, the president still tours the country tirelessly, holding party meetings, cutting ribbons and, most important, giving speeches to approving crowds — three per day on average, most of them broadcast live on multiple news channels.

Economists say that Turkey’s economic crisis has been caused primarily by Mr. Erdogan’s mismanagement — unsustainable borrowing, cronyism and huge public works projects with little economic return — and now, he carries almost single-handedly the burden of steadying the nation. Mr. Erdogan may not have solutions for his nation’s troubles, but so far he has deflected blame, relying on nationalism, resentment of the West, his firm grip on the country’s news media and his own formidable popularity and political skills.