John McCain was elected to the US Senate in 1986 and has served continuously since.
lamar has served for 9 years in the senate bob has served for 4 years in the senate
He served from 2005 to 2008.
Nader has never served in the US Senate.
John McCain represented the state of Arizona in the United States Senate.
2 Years
You look at how long each has served in the senate. The one who has served the longest is the "senior senator."
There were 25 US presidents who never served in the Senate.
in Arizona
The people of Colorado elected Mark Udall to the U.S. Senate in 2008. http://www.markudall.senate.gov/?p=about_mark
country first
johnson
Julius Caesar served in the senate and took on the powers of a king during his numerous dictatorships. Octavian/Augustus could also be loosely included in this answer, as he forced the senate to declare him consul, although he never actually served in the senate before this.