I see we completely disagree on this. After 36 years of following American politics as a conservative Republican and political junkie, my take is different then yours. You never, ever allow the loyal opposition to run a candidate for a seat in the US Senate unopposed. Never! Statewide election, maybe. In local community elections it happens all the time. The GOP needs to find the best candidate and run with him or her.
I don't think the GOP can beat him and he will enter the Senate not knowing how strong he is and more importantly he will remain politically untested until 2010.