Hillsborough will be really interesting to watch imo. The County has been remarkably stagnant Presidentially since 2008 (D+7), but recent regristration and 2022 makes it seem like the County could lurch right and even flip in 2024. Miami-Dade and Hillsborough have the chance to be the 2 largest Republican voting counties nationally.
Despite it's consistency Presidentially the County has always seemed to be a bit more favorable to Republicans downballot - Rubio carried it in 2016 and Scott in 2014 for instance, so 2022 results may be a bit misleading - especially since Dems didn't do uniquely bad there in the context of the state in 2022.
Crist carried Hillsborough in 2014, although just barely.
Pinellas and Pasco are more similar than Pinellas and Hillsborough. In Hillsborough, I'd estimate the 55% of Whites have a college degree. That might be 40% in Pinellas and 30% in Pasco.
Hillsborough definitely is more typically Southern. More class and racial polarization. South Tampa is very similar to Buckhead in Atlanta. Pinellas and Pasco have demographics more like someplace like Saginaw County, MI than Tampa, Atlanta, Charlotte, etc. Interior Pinellas and the Pasco Coast are filled with heavily White trailer parks that loved Clinton, Gore, and even Obama through 2012. These communities have unsurprisingly swung massively to Trump, but they remained Dem for a long time, and backed Crist to a hilt in 2014.
Holiday, FL (Southern Coastal Pasco, pop 25k):
75% White, 15% Hispanic, 7% Black, 11% Bachelor's attainment
2000: D+14
2012: D+10
2014: D+13
2016: R+15
2020: R+19