It was one of the issues that propelled Donald J. Trump into politics: his obsession with President Obama’s birth certificate.

After months in which “birtherism” dominated cable news and the political dialogue, the issue eventually petered out after Mr. Obama released his long-form birth certificate.

But that, apparently, is still not enough for some, including Mr. Trump’s former campaign manager, Corey Lewandowski.

Now a paid commentator on CNN, Mr. Lewandowski brought up the issue anew Tuesday night in an argument with Angela Rye, another political commentator on CNN.