Unfortunately all it would take is a fast deployment tactic dedicating everything the US has. It comes down to raw numbers of immediately available manpower, aircraft, and munitions. The US has a stupid amount of these things at the ready.
It would be bloody and brutal and not certain, but I'd say the US would have a decent chance of overrunning the country.
Now this will only topple the government, then you get into a whole Afghanistan situation again. So I suppose it depends on what the definition of victory is. Could the US defeat Iran and occupy it? I think it's likely, but the second they leave a new government that hates the US (rightfully) forms. Could they occupy indefinitely? Probably at a steep cost.
So I see a path for the US to overwhelm the Iranian military, but no real way for them to ever establish control of the region. I wouldn't call that a win for the US for sure