If Cardin(D-MD) retires from the US Senate in 2024. The Democratic Primary winner is unknown.

The top tier candidates are going to be
Prince George’s County Executive Angela Alsobrooks.
US Representative Jamie Raskin.
US Representative John Sarbanes.

Alsobrooks is the only non white female candidate in that race. She could finish in 1st place in Prince George’s, Charles, and Baltimore City, 3 Counties/Cities that have majority black population. Alsobrooks is also popular with all 4 of the MD statewide elected officials.
Governor Wes Moore.
Lt Governor Aruna Miller
Attorney General Anthony Brown
Comptroller Brooke Lierman.
Alsobrooks helped all 4 of them win the primary and general election.
Raskin is the most progressive candidate in that race and is an excellent fundraiser.

We know who the Democratic nominee is going to be in
AZ-(Gallego-D)
CA-(Schiff-D)
CT-(Murphy-D)
DE-(Blunt Rochester-D/if Carper-D retires.)
HI-(Hirono-D)
ME-(King-I/D)
MA-(Warren-D)
MI-(Slotkin-D)
MN-(Klobuchar-D)
MT-(Tester-D)
NV-(Rosen-D)
NJ-(Menendez-D)
NM-(Heinrich-D)
NY-(Gillibrand-D)
OH-(Brown-D)
PA-(Casey-D)
RI-(Whitehouse-D)
VT-(Sanders-I/D if he decides to run again. If Sanders retires, it will be Becca Balint-D or Charity Clark-D.
VA-(Kaine-D)
WA-(Cantwell-D)
WV-(Manchin-D)
WI-(Baldwin-D)