Nearly 40 Republican lawmakers are calling on President Biden, 79, to take a cognitive test, following the example set by his predecessor, former President Donald Trump.

The Republican push for Biden to undergo cognitive testing comes as recent polls have shown Americans are unsure of the president’s mental fitness for office.

Former physician to the President Rep. Ronny Jackson, R-Texas, led a letter with 37 of his GOP colleagues to Biden on Tuesday expressing their “concern” with Biden’s “current cognitive state.”