Even had Flynn been sentenced Trump doesn't have the authority to suspend the sentence. He can pardon him but sentences are acts of the court and separate from the Executive branch.
Not really. He can commute a sentence if he wants. He can also nullify it with a pardon. A president can commute it which essentially is even more powerful than suspending it.
What is the difference between commuting a sentence and a ...
https://www.fox13memphis.com/news/trending/what-is-difference-between-commuting-sentence-pardon-who-can-president-pardon/JVVOD66UQFHXVK2J22ULOIIPEE/
President Donald Trump is expected to commute the 14-year prison sentence of Blagojevich. The 63-year-old Democrat is expected to walk out of prison later Tuesday, Feb. 18, 2020. (M. Spencer Green/AP)
I respectfully disagree.
For example, President Trump has commuted the sentence of Rod Blagojevich. He was not pardoned.
Also, WRT Scooter Libby: "After denial of Libby's bond by the U.S. Court of Appeals for the D.C. Circuit, President Bush commuted the prison term portion of Libby's sentence on July 2, 2007, leaving in place the felony conviction, the $250,000 fine, and the terms of probation (supervised release)."
The president can commute a sentence.
A commutation is the mitigation of the sentence of someone currently serving a sentence for a crime pursuant to a conviction, without vacating the conviction itself.
PART V
THE UNION
CHAPTER I.-THE EXECUTIVE
The President and Vice-President
Article 72. Power of President to grant pardons, etc., and to suspend, remit or commute sentences in certain cases.-
(1) The President shall have the power to grant pardons, reprieves, respites or remissions of punishment or to suspend, remit or commute the sentence of any person convicted of any offence-
(a) in all cases where the punishment or sentence is by a Court Martial;
(b) in all cases where the punishment or sentence is for an offence against any law relating to a matter to which the executive power of the Union extends;
(c) in all cases where the sentence is a sentence of death.
(2) Nothing in sub-clause (a) of clause (1) shall affect the power conferred by law on any officer of the Armed Forces of the Union to suspend, remit or commute a sentence passed by a Court Martial.
(3) Nothing in sub-clause (c) of clause (1) shall affect the power to suspend, remit or commute a sentence of death exercisable by the Governor _52*** of a State under any law for the time being in force.