This thread was inspired by this Gubernatorial thread.
As far as the Atlas goes back, I found these results:
Obama, IL (2004) 69.97%
Crapo, ID (1998) 69.54%
Bayh, IN (1998) 63.72%
Reed, RI (1996) 63.48%
Roberts, KS (1996) 62.02%
Does anyone have any guesses as to other non-incumbents who won a comparable percentage for their first term?
Byrd, WV (1958) 59.19%
Kennedy, MA (1962) 55.44%
Inouye, HI (1962) 69.41%
Stevens, AK (1970) 59.61%
Biden, DE (1972) 50.32%
Domenici, NM (1972) 54.02%
Leahy, VT (1974) 49.48% - Bernie Sanders with 4.13%
Sarbanes, MD (1976) 56.55%
Lugar, IN (1976) 58.76%
Hatch, UT (1976) 53.74%
Baucus, MT (1978) 55.68%
Cochran, MS (1978) 45.05% - Charles Evers with 22.89%
Warner, VA (1978) 50.19%
Levin, MI (1978) 52.14%
Dodd, CT (1980) 56.34%
Grassley, IA (1980) 53.36%
Specter, PA (1980) 50.48%
Lautenberg, NJ (1982) 50.94%, first tenure.
Bingamon, NM (1982) 53.77%
Kerry, MA (1984) 55.06%
Harkin, IA (1984) 55.47%
McConnell, KY (1984) 49.91%, Socialist Worker with 0.60%.
Rockefeller, WV (1984) 51.82%
So for the 23 most senior members, only Inouye is above 60%.