Judicial v. executive branches: Chief Justice John Roberts watches President Obama sign the guest book of the Supreme Court (Credit: Gage Skidmore)

The suspension of Rick Santorum's campaign for the Republican presidential nomination was a sensible move, both for the GOP and himself. He will be 58 when he runs again in 2016; or, if Romney wins the presidency this year and therefore is unopposed in 2016, Santorum will only be 62 should he run in 2020. (The reason why candidates such as Santorum, Herman Cain and Rick Perry "suspend" rather than "end" their campaigns is a legal/financial one to do with the paying-off of campaign debts with contributions, but in effect a suspension equals a termination.) 

Mitt Romney is therefore going to be the Republican nominee, barring anything short of assassination, although it will be interesting to see how many diehard conservatives so dislike him that they ignore party unity and remain voting for Newt Gingrich, whose campaign continues despite its having bounced a $500 cheque recently. Gingrich's erratic pronouncements — including the demand that the United Nations should campaign for the right to bear arms as "a human right for every person on the planet" — add to the jollity of American politics, but do not affect Romney's now leisurely amble to the nominating convention in Tampa, Florida, in August.  

Yet it was not to Romney, Santorum or Gingrich that politically-minded Americans have been turning their minds in recent weeks, so much as to the real possibility that President Obama's signature political initiative of his first term — the Patient Protection and Affordable Care Act (or "Obamacare") — might be struck down as unconstitutional by the Supreme Court. Over three days in late March, the court heard the Solicitor-General, Donald B. Verrilli Jr, argue that Obamacare, and in particular its "individual mandate" that requires most Americans to acquire health insurance or pay a penalty, did not violate the Constitution. The six men and three women in black robes seemed unconvinced. By the end of Verrilli's cross-questioning by conservative justices such as Antonin Scalia and Samuel Alito, the online prediction market Intrade had raised its odds on Obamacare's rejection from 33 per cent to over 60 per cent. An announcement is not expected until June, but the court has already made its decision in camera. 

It is sometimes hard for non-Americans to appreciate just how powerful the Supreme Court is. The idea that Obama's most important law might simply be struck down by a 5 to 4 decision, despite having been explicitly campaigned on in the 2008 election and passed by both houses of the legislature, surprises those of us who come from countries without written constitutions. Yet such a thing happens regularly in America, a country founded on a revolutionary document rather than evolving from a post-feudal monarchy.