Santorum: Latin for McGovern?

I finally had a chance to look into something that's been in my mind since the election. I noticed that Rick Santorum didn't just lose his Senate race, he got crushed, 41.3 to 58.7 percent. Incumbent Senators sometimes lose reelection, but incumbency advantages being what they are, not by this much. Plus, Senators in serious trouble usually retire rather than risk defeat and public humiliation. That got me wondering whether this was some kind of a record for worst defeat for an incumbent senator at the end of a full term (John Seymour R-CA lost with 38 percent of the vote in 1992, but he was appointed to the seat when Pete Wilson left to become governor--voters can't necessarily be held responsible for tossing out someone they never picked in the first place). It turns that Santorum's is the worst showing for an incumbent Senator in over 25 years. In 1980, George McGovern lost to James Abdnor with only 39.4 percent of the vote. Of course, McGovern was running against the Reagan landslide, so Santorum might still hold the record for a midterm loss.