A review of the Wikipedia biography of Senator Gregg of New Hampshire leaves the President's nomination of him to be the next Secretary of Commerce pretty much a mystery. The only pertinent details I saw were his ranking as a "free trader" by a libertarian group and his patronage of environmental technology research in his home state via earmarks. Perhaps Obama looks to Gregg to help implement some of his "green job" schemes. More likely it's another pointless attempt at "bipartisanship" when "non-partisanship" should be the idea. There is a difference, which is demonstrated plainly enough by Gregg's reported insistence that the Democratic governor of New Hampshire appoint a Republican to replace him when he enters the Cabinet. A non-partisan would not care who followed him.
If anyone needed more proof of the necessity of the Constitutional amendment proposed by Sen. Feingold, which would force special elections to fill all U.S. Senate vacancies, here it is. The voters of New Hampshire chose a man named Judd Gregg as their Senator. They did not choose the Republican party. We can assume safely that some people would not have voted the Republican line had a different person been the candidate, while others might have who didn't want to vote for Gregg. Despite all the rule-mongering of party lines on ballots, citizens vote for people, not parties. Whatever Gregg or his fellow Republicans want to believe, Gregg's seat does not belong to the party. As things stand, it's the governor's prerogative to appoint whom he pleases. The executive is answerable to no one. The only leverage Gregg has against the governor is the threat not to accept Obama's invitation to serve in the Cabinet. Since I don't think that Obama is scheming to put in an extra Democrat and get the filibuster-proof majority, he would most likely lean on the governor to accept Gregg's terms. So now even a bad law is effectively overruled by the intrigues of the American Bipolarchy. Under current conditions, the Bipolarchy won't be harmed by a special election, though Republicans in New Hampshire might resist it on the assumption that they'd lose, so there's really no good reason for the political establishment to oppose the Feingold amendment when it comes. You may hear reasons, but they won't be good ones.