A President’s pardon authority is limited to federal crimes. Junior was convicted of a federal crime in federal court, so Brandon can and will pardon Junior sometime after the November election and before Trump is sworn back into office in January.
That is what has always worried me about the sham criminal cases against Trump in New York and Georgia. They are state charges, so Trump cannot pardon himself when he takes office. He will have to appeal any convictions and try to get them thrown out. Most likely, the state appellate courts won’t overturn any conviction of Trump, no matter how groundless. His only chance of reversal is if the Supreme Court takes the case and reverses it either based on Presidential immunity (not likely) or violations of due process and Trump’s civil rights.
Opinions vary.
I prefer to go by actual history.
“Republican president Richard Nixon pardoned, commuted, or rescinded the convictions of 926 people. Among them are: Jimmy Hoffa – prominent labor union leader convicted of fraud and bribery (tax evasion) in 1964; sentence commuted (with conditions) on December 23, 1971.”
Some of those were state level crimes.