“But the reason they’re speaking up is because they have seen that in Donald Trump’s mind, the military does not exist to serve the Constitution or the American people,” Obama said. “He doesn’t see being commander in chief as a solemn, sacred responsibility. Just like everything else, he thinks the military exists to do his bidding.”

The former president hit out at the Republican presidential candidate at his first joint rally with Kamala Harris.

Trump's ex-chief of staff told news outlets this week that the former president praised Adolf Hitler on multiple occasions.