As far as "rising stars" that might be major players in 2024, one really sticks out in my mind: Missouri Governor Eric Greitans. If he's reelected in 2020, then 2024 will coincidence with the end of his second-term as governor - perfect timing for a Presidential run. He'll be relatively young (only 50 in 2024), he's unabashedly conservative, Jewish, a former Navy SEAL and Rhodes Scholar, and (based on what I've seen so far) might be the perfect Republican to bridge the South/Midwest and Trump/religious right divides. He's all the advantages of Pence x10, plus youth, without the Trump baggage.
The only way this guy isn't a GOP nominee one day is through some sort of major self-inflicted wound.
if he only knew
https://www.stlmag.com/news/can-eric-greitens-become-missouri-s-next-governor/. From this article (published before he even won the primary):
If the man has an Achilles’ heel, it’s perfection.
Now he’s running for governor, and Missouri has to decide whether he’s A. Superman, B. too good to be true and hiding some dark flaw no one can find, or C. a strategist whose entire life has been planned as a ramp to the U.S. presidency.