Who will be the next senator from New Mexico?

[Meatball Ron]

The challenge here, like you point out, is that both of NM's Senators are fairly young and could stick around for a while. It could be 20 years until a Senate seat opens up, for example - unless one of the current Senators ends up as a running mate to a female Democratic presidential nominee.

Teresa Lager-Fernandez, the new Rep. for NM-03, seems like a good bet in the event that a seat opens up in the next 10 years, but if Heinrich and Lujan both stick around until they're of retirement age, she'd likely be too old. I'd also keep an eye out for whoever ends up replacing Haaland in NM-01 (depending on that person's age). And I'm sure we haven't seen the last of XTS, who is also very, very young. NM-02 is likelier to get bluer in redistricting, but I suspect it'll still lean red, because drawing three Dem districts in NM comes with serious dummymander risk. She is more on the conservative side, but could definitely pull a Gillibrand and pivot left when running statewide rather than in a R-leaning House district.

[Meatball Ron]

Three of the most obvious candidates (MLG, Haaland, and TLF) are all over a decade older than either senator, so it probably won't be any of them unless one of the senators has to retire or resign due to extenuating circumstances. Could totally see XTS, Morales, MTO, or Balderas.

It's interesting - between the two Senators, the three row officers you mentioned, and XTS - New Mexico has so many young, Democratic politicians. Even their "old" politicians like MLG, TLF, Haaland, and Colon are in the 50-60 range, as opposed to the 65-80 range we see in a lot of other states. Wonder why that's the case.