Some on Twitter think Trump sang the national anthem incorrectly. Watch for yourself 

President Donald Trump speaks before signing an executive order on health care. (Photo: Evan Vucci/AP)

The College Football National Championship had just begun, and Twitter was already on fire. 

That's because President Trump came onto the field of the Mercedes-Benz Stadium Atlanta to a mix of cheers and boos before singing along to Zac Brown Band's performance of the national anthem.

Trump stood on the field and sang the anthem with his hand over his heart. The TV broadcast didn't pick up what Trump was singing, but Twitter already made up its mind: The president didn't know the words to The Star-Spangled Banner.

Twitter