When historians look back on the Obama administration, they may deem the senatorial election in Massachusetts on Jan. 19, 2010, to have been the pivotal event determining its destiny.

That day, conservative Republican Scott Brown handsomely defeated liberal Democrat Martha Coakley to become the state's first republican senator in almost 40 years — and that despite the president's personal intervention in Coakley's campaign. This event will, I believe, impact not only this year's midterm congressional elections but also the 2012 presidential election.

Unlike in the United States, it is almost routine in Britain for voters in such a by-election to deliver a warning to the party in power with a slap on the wrist. But this special election in Massachusetts, to fill the seat left vacant by the death of Sen. Edward Kennedy on Aug. 25, 2009, delivered the administration of President Barack Obama not so much a slap on the wrist as a swift kick you-know-where.