The special election in Massachusetts appears to be, at the very best, uncomfortably close for the Democrats’ taste. More pessimistically, the seat may well be lost to the Republican candidate.

How is that possible, some may cry. After all, this was the seat held by Ted Kennedy, who held the seat for 46 years.

But why must a Senate seat held by a member of one party for many years be retained by that party on the death or retirement of the incumbent? History is full of examples of party switches:

1983: Henry Jackson (D-WA), who held the seat for 31 years, was succeeded by Dan Evans (R)

1968: Carl Hayden (D-AZ), who held the seat for 42 years, was succeeded by Barry Goldwater (R)

1974: George Aiken (R-VT), who held the seat for 33 years, was succeeded by Patrick Leahy (D)

1978: James Eastland (D-MS), who held the seat for 36 years, was succeeded by Thad Cochrane (R)

1988: John Stennis (D-MS), who held the seat for 41 years, was succeeded by Trent Lott (R)

2004: Ernest Hollings (D-SC), who held the seat for 38 years, was succeeded by Jim DeMint (R)

2008: Pete Domenici (R-NM), who held the seat for 34 years, was succeeded by Tom Udall (D)

The affection voters have for a long-standing incumbent may be for them alone, not the party. The politics of states can change over a long tenure. Or maybe, as in Massachusetts, voters may be sufficiently ticked off at events to throw the bums out. Even so, if Martha Coakley wasn’t an unattractive candidate of almost limitless ineptitude this one would be in the bag for the Democrats.