There was a time when a matchup like this may have been interesting, but by 1990 Camacho was not the same and Whitaker would have beaten him. Probably a painfully boring fight by that time.
I read somewhere, possibly here back in the day, that they sparred in the mid 80's and Whitaker absolutely toyed with Camacho. A bit surprised to hear that. Camacho has his best chance by dazzling the judges with flurries to end the round. Whitaker 8-4 in a dull fight.
As far as pure talent both Camacho and Whitaker were almost carbon copies of each other, and their lives were tragically parallel. Both were seen as can't miss prospects, both had dominant performances over very good opposition early on that enhanced their early careers. Both got into drugs , and those issues seemed to lead to both of their untimely ends. ( Definitely with Camacho, some say Whitaker was cleaning up his act when he was killed.) This wouldn't be an easy fight for either man if they were prime. And for some to insinuate Camacho wouldn't have a chance against Whitaker is crazy in my opinion. Hector Camacho was one of the most gifted boxers of the 80's physically, and could do what no opponent Whitaker faced could do. Match his speed and quickness. Camacho at Jr. Lightweight before the drugs started to take their toll was a machine, and anyone that deny's that fact did not see him at his very best . It's very conceivable that they could nullify each other in their primes, and a boring fight would happen. I do believe Whitaker wins, but not because he was much faster or more powerful than Camacho, or better skilled ( he wasn't) but because he'd more than likely take the initiative and press the attack . That would be the difference, Whitaker's ability to be aggressive when necessary, and take the win.
In 1990 ? i think Whitaker wins a clear decision. Around this time Whitaker was at his peak with stand out performances vs the likes of Azumah Nelson, Greg Haugen, Jose Luis Ramirez 2nd fight. Camacho around this time was struggling to beat a faded Ray Mancini who hadn't fought in 4 years, and also lost to Greg Haugen who Whitaker toyed with. If you're talking about a prime Camacho in the early to mid 80s ? then Camacho runs Whitaker closer but still loses a decision but it would be a better fight.
I think Whittaker’s skill and defense negates Camacho’s blinding speed in a close and probably dull decision