ISTANBUL — Having already brought Turkey’s mainstream media to heel, and made considerable headway in rolling back Turkish democracy, the government of President Recep Tayyip Erdogan has set its sights on a seemingly innocuous target: a satellite television preacher named Adnan Oktar.

For seven years, with an unholy blend of the racy and the religious, Mr. Oktar has presented his show daily via satellite, cable and the internet, where he expounds on Islamic creationism, peace and love, often to a studio audience of women in miniskirts and plunging necklines.

Religious conservatives in the government now say they want to shut him down. But critics say that Mr. Oktar has become a convenient trigger for the government to pursue wide-reaching restrictions on internet content and broadcasters.

The real aim, they say, besides enforcing moral standards on the likes of Mr. Oktar, is to close off a final refuge for the news media and the political opposition as the government widens an already formidable crackdown on dissent.