Yes she is the senior Senator and Susan Collins is the junior Senator.
The difference is that the senior Senator has been in office longer than the junior Senator.
Maryland senior senator is Sen. Barbara Mikulski. Maryland junior senator is Sen. Bejamin Cardin.
Each state has 2 senators. The one who has been in office the longest is the senior senator.
Senator Susan Collins represents Maine in the U.S. Senate. Senator Susan Collins represents Maine in the U.S. House of Representatives.
He is the senior senator from Arizona.
There are 2 senators from each state each serving 6-year terms. The senator with the longer term in office is known as the "senior" senator while the other is known as the "junior" senator.
Daniel Inouye.
He is the senior senator from Arizona.
Carl Levin.
Dianne Feinstein
Hugh Segal