Who is one Senator, Representative, and Governor from each party that you think can become POTUS?

[Ferguson97]

Democrat:
Governor: Gretchen Whitmer
Senator: Jon Ossoff
Representative: AOC

Republican:
Governor: Ron DeSantis
Senator: Josh Hawley (or maybe Josh Mandel, if he wins. Incumbent GOP Senator bench is kinda rough.)
Representative: Lauren Boebert

[VirginiaAaron]

Democrat:
Governor: Gavin Newsom
Senator: Cory Booker
Representative: Lauren Underwood

Republican:
Governor: Greg Abbott
Senator: Tom Cotton
Representative: Nancy Mace

[Del Tachi]

The earliest opening for a non-Biden-or-Harris Democrat to be nominated is realistically 2028, which is forever in politics.  Best guesses for governors would hence be someone term-limited out after 2026, probably Jared Polis.  Newsom and Whitmer have proven too polarizing to bet on their popularity six years out. 

Same thing for Democratic senators, you need someone who is already keyed-up to win reelection in 2022/24 before making a successful run in 2028.  Democrat runner-ups/also-rans (i.e., Al Gore, Hillary Clinton, etc.) tend to not do very well with the national electorate so I don't think it'd be a previous 2020 contender.  I'd guess Ossoff. 

The only House member with a national profile high enough to conceivably win the nomination in 2028 as of right now is AOC, but there are multiple House members who could get elected to higher office in 2022/24 prior to making a successful run in 2028:  Ruben Gallego, Greg Stanton and Conor Lamb all fit this category, among others.

Republicans are significantly easier to guess because there's likely to be an open 2024 field.  The obvious answer for governors is DeSantis.  Cruz seems like a good pick for senators just because he's almost certain to run with and be in contention for the bulk of conservative support.  House members who could run in 2024 include Crenshaw, Gaetz and MTG, with Crenshaw probably being the most likely to emerge as the nominee. 

So my answers are:

Dems - Polis, Ossoff and Lamb
GOP - DeSantis, Cruz and Crenshaw

[Thank you for being a friend...]

Reds:

House: Dan Crenshaw (TX), Maria Elvira Salazar (FL), Nancy Mace (SC), Mike Gallagher (WI)
Senate: Lyin' Ted Cruz (in all seriousness he could), "Little Marco"?
Governors: Not Good Ol' Charlie (MA), sadly... Kristi Noem (SD), Ron DeSantis (FL)

Blues:

House: Val Demings (FL), Colin Allred (TX), Sharice Davids (KS), AOC (NY), Ritchie Torres (NY)
Senate: Mark Kelly (AZ), Tammy Duckworth (IL), Raphael Warnock or Jon Ossoff (GA)
Governors: None

[GregTheGreat657]

Democrats:
Governor: Roy Cooper
Representative: Conor Lamb
Senator: Tammy Duckworth

Republicans:
Governor: RDS
Representative: Crenshaw
Senator: Marco Rubio

[Leroy McPherson fan]

Dems
Governors: Phil Murphy
Senators:  Amy Klobuchar, and John Hickenlooper
Reps: AOC

GOP
Governors: Ron DeSantis and Kristi Noem
Senators: Ted Cruz, Marco Rubio, Tom Cotton, Tim Scott, Rick Scott and Josh Hawley
Reps: Dan Crenshaw