Jeffrey Toobin says Joe Biden tarnished his legacy by pardoning his son, and Donald Trump cemented one of the knocks against him with his own slew of presidential pardons.

The lawyer, author and legal analyst joined us on “TMZ Live” Wednesday and he told us how presidents reveal their true colors when it’s time to hand out pardons.

Jeffrey wrote a new book on the subject, “The Pardon: The Politics of Presidential Mercy,” and says pardons are one of the few powers a president has that are free from checks and balances — and that’s why they tell so much about the men giving them out.

He says Biden revealed his family comes first when he pardoned Hunter … explaining how going back on a promise not to pardon his son torpedoed Joe’s legacy.

Trump handed out pardons like candy at the end of his first term and he pardoned a ton of folks who were convicted for the Jan. 6 riots … and Jeffrey says it’s part of Trump’s transactional nature.