The cinematic journey taken by Harry Potter spanned an entire decade, starting in 2001 and culminating in 2011. The franchise was a massive success, not just for its fantastic sets and shimmering CGI, but also due to its incredibly skilled cast. At this point, it's nearly impossible to imagine Harry Potter and not see Daniel Radcliffe's face instantly.
This is exactly why considering the narrative through the lens of the 1980s would be a fun thought experiment — in how many ways would the actors from that period be able to accurately play the characters whose entire lives were set in the early to mid-nineties?
Harry Potter — Ralph Macchio
When it comes to spunky teenagers who have to unlock ancient secrets in order to take down their bullies (physically and emotionally), there is no need to look any further than Ralph Macchio, best known for Karate Kid (1984) and its two sequels.
Like Harry, Daniel LaRusso moves to a new school where a bunch of "karate jocks" constantly harass him, at least until he proves that he is fully capable of defeating them on even ground and using their own techniques against them. Not to mention how acerbically sassy both of them are.
Albus Dumbledore — Pat Morita
If Ralph Macchio is to play Harry Potter, then Paul Morita (Daniel's sensei) has to be Albus Dumbledore. They are both old men, extremely accomplished in their respective crafts, and understand the true value of love and peace, unlike John Kreese and his Cobra Kais.
Most importantly, Mr. Miyagi's comic style — eccentric and inscrutable — reflects perfectly that of the Hogwarts Headmaster himself. Besides, the whole student-teacher bond narrative cannot be ignored.
Lord Voldemort — Jack Nicholson
Jack Nicholson is capable of handling any role under the sun: psychotic authors, charming criminals, kindly father figures, stubborn old men with OCD, to name a few. One of his greatest strengths though appears in Jack Torrance from The Shining (1980), and The Joker from Tim Burton's Batman (1989).
Nicholson doesn't hesitate to lose himself in performance, which is how he's able to tap into the deepest reserves of human emotion and sculpt each character out with fantastic finesse. Who else would be able to play Lord Voldemort?
Hermione Granger — Mia Sara
Mia Sara's major role is as Sloane Peterson, in Ferris Bueller's Day Off (1986); what seems like a supportive act is only a facade, however, as she hardly fades into the background whenever Ferris takes the reins of the storyline.
This resembles, in many ways, the part Hermione Granger plays in The Golden Trio: she is narratively sidelined in favor of Harry's POV on several occasions, but always comes back into the picture and saves the day when the two boys are stumped. Secondary, but as crucial to the plot.
Professor Snape — Robert De Niro
Professor Snape is a delicately designed character, intended to serve as a foil for the antagonist at the conclusion of the story. Therefore, his interpretation by Alan Rickman, as a slow-speaking, expressionless, potentially-evil wizard turned antihero is undeniably excellent.
Doing Snape with Robert De Niro at the helm would result in a drastically different personality, but, as proven from Taxi Driver (1976), Raging Bull (18980), and, most unusually, Brazil (1985), he is certainly versatile enough to make it work.
Ron Weasley — Kirk Cameron
Kirk Cameron's 1980s heartthrob status notwithstanding, he was also a skilled actor, for example, in Like Father Like Son (1987) and Listen to Me (1989). The reason he is ideal for Ron Weasley is largely due to the teenage Mike Seaver in Growing Pains, a popular TV show that began in 1985.
While Mike is not really anything like Ron, the fact remains that Cameron knows how to depict the inner world of an adolescent with incredible accuracy, suggesting that a minor personality alteration is the only thing necessary to transform him into the jittery, red-headed deuteragonist.
Draco Malfoy — River Phoenix
River Phoenix, Joaquin's older brother, was an incredibly popular eighties star, especially with Explorers (1985) and Stand by Me (1986). Interestingly, he showed that he was just as capable of serious roles, like in Running on Empty (1988) and My Own Private Idaho (1991).
In order to realize the character of Draco Malfoy, a young boy filled with insurmountable insecurities, a vast amount of emotional poise is essential, which Phoenix had no shortage of.
Bellatrix Lestrange — Sigourney Weaver
Helena Bonham Carter does Bellatrix Lestrange with a fiery hostility that few others can muster, but that's if one doesn't consider Sigourney Weaver in the part. She usually plays the hero trope to perfection, albeit in an unorthodox manner.
Further, she's almost six feet in height, and Bellatrix has been referred to as a tall woman by the author, so Bonham Carter's diminutive size doesn't exactly match this aspect of hers. Finally, anyone who has watched Ellen Ripley blast her way across a horde of Xenomorphs will be able to picture her blasting her way across Hogwarts.
Sirius Black — Tom Cruise
Sirius Black has been described as "handsome and full of laughter", which is the very definition of 80s Tom Cruise. Risky Business (1983) and Top Gun (1986) established him as a proficient actor, while simultaneously making him a household name due to his effortless good looks and charisma.
Of course, there would need to be some amount of make-up work to get him to look the appropriate age, but this is not really all that difficult to make happen.
Professor McGonagall — Elizabeth Taylor
Elizabeth Taylor's career has seen some truly spectacular highs — from her preteen Velvet Brown in National Velvet (1944) to the combustible Maggie Pollitt in Cat on a Hot Tin Roof (1955) to the awe-inspiring title character in Cleopatra (1963).
She could do anything, including a magical professor with a penchant for the rules hiding a secretly compassionate heart. Dame Maggie Smith did Minerva McGonagall justice, but one can wonder how Elizabeth Taylor would have added her personal flair to the role.