That was the argument used by the "conservatives" who endorsed Arlen Specter for re-election in 2004 "after this term, he'll retire anyway!". Nope, Specter ran for re-election in 2010 when he was pushing 80. Daniel Inouye just announced he's running for re-election to ANOTHER 6 year term in 2014, when he'll be in his 90s. These Senators won't leave until they'll defeated or carried out feet first.
>> I confess that I don't understand... <<
I confess I don't understand your argument either.
But I think I've got it now...
You'd prefer a candidate who wants to raise taxes and is somebody you don't trust over the incumbent because...well, because the incumbent is the incumbent.
Isn't that about it?