How would Marvin Hagler have done in the 80s LHW division

Nobody would take that shot

 

Hagler had a longer reach and better jab than Tiger plus he was a southpaw, not all light heavies had one punch power like Foster.

 

Marvin was a great natural middleweight .. he would not have defeated the top light heavyweights of the late 70's to early 80's ..

 

Hagler was the perfect Middleweight. The division fit him like a glove. Even after he retired it didn't look like he gained much weight.
I don't believe Hagler would have much success against the better Lt.heavyweights of the era.
He wasn't a devastating puncher at Middleweight, so would he have the fire power to keep a fighter like Qawi or Muhammad off of him. Could he gain their respect. I don't believe he could. It would end up a disaster for him at Lt.heavy.

 

Both of them had ko power, both were well schooled, so take your pick .

 

Hagler fought in an era where you weighed in on the day of the fight a few hours before the card began.

And he routinely weighed well under the middleweight limit.

Middleweights today are in the 170s when the bell rings, if not 180s. It wasn't like that back then.

Hagler fought at middleweight his whole career because he fought his best in the ring weighing under 160 pounds. He didn't move up because he knew his place. He was a middleweight.

Other than the number of sanctioning bodies, moving weigh-ins to 30 hours before a fight probably altered the course of boxing history more than anything.