The state of Maine has two popular 'moderate' GOP senators. One of them Collins is a faux moderate who vies with McCain for the title of Bush's 'sidekick'. The other senator, Olympia Snowe is proably a true moderate at heart, but lacks the political courage to make any true breaks with the Republican Party where it counts.
While the Collins problem may sort it self out in the election providing Tom Allen can make an aggressive enough run for it, Snowe's by far the more popular of the two and isn't going away anytime soon.
I suggest giving Snowe an honorable way out of her quandry by having a President Obama appoint her to a minor cabinet position in the name of 'bipartisinship' or perhaps a cozy ambassadorship in a quiet, comfortable country.
Subsequently the governor of Maine, a Democrat, could appoint her successor. No doubt his choice will be made in all impartiality.