The POTUS doesn't control inflation, market forces do (You do understand what market forces are, right? They're that inherently and inextricably determinant, directive, steering factor of all capitalist economies).
Of course, as the subject is inflation & you seem bound and determined to make this about politics rather than reality, let's talk about the only government agency with the ability to control inflation... you know... the Federal Reserve. Remind me: Jerome Powell's in charge of the Fed., isn't he? If memory serves, he's a republican. He was appointed by Trump, wasn't he? And, as political affiliation is apparently the convenient focus of blame, the causative, lurking beast behind inflation in your mind, does it not follow that, as Jerome Powell is in charge of the Fed., the GOP is therefore responsible for inflation in the U.S.?
Huh... interesting how the rules of your own game neatly tie the United States' inflation issues up in a bow and lay them all right at the elephant's feet, innit?
Funny thing, that...
Of course, you could come back to reality and acknowledge that all economies on the planet are linked to each other through supply chains and that tugging a thread anywhere on the planet will cause impact world-wide... but that'd get in the way of your political narrative, wouldn't it?