AND then there were two. Former Massachusetts governor Mitt Romney will not officially become the Republican nominee for president of the United States until the party convention in August, but his victory in this week's Texas primary ensured the nomination is his. Mr Romney now has the 1144 convention delegates whose support he needs, and on Tuesday, November 6, he will contest the election against President Barack Obama.

In theory at least, Mr Romney can now concentrate on presenting himself to American voters as a credible alternative to Mr Obama, instead of assuring fellow Republicans that he is conservative enough to be accepted as their leader. Even on the day that he clinched the nomination, however, Mr Romney was reminded that other Republicans may continue to be liabilities in his campaign.

Donald Trump, a staunch Republican and icon of corporate America with whom Mr Romney has been closely associated, gave a television interview in which he revived the accusation that Mr Obama holds office illegitimately because his birth certificate is forged. It is a bizarre claim, without foundation, that panders to those who believe the President must be a Muslim because of his given names, and who probably also believe that a black man should not occupy the Oval Office. It is not a view Mr Romney holds, but the fact that he could not publicly repudiate a prominent supporter who does hold it is an indication of how far the Republican Party has moved to the right.

It was hardly the start to the real campaign for the presidency that Mr Romney would have wanted. He would no doubt prefer to concentrate on attacking the Obama administration over America's weak economic recovery, and on trying to persuade women voters that he is not their enemy, whatever he may have said about abortion and working mothers during the primary campaign. Opinion polls suggest that he is indeed regaining support among women, though he still trails the President. And persistent anxiety over unemployment - especially in crucial ''swing'' states - certainly helps him, simply because it is always a liability for incumbents.

As a former corporate raider during his time with the investment firm Bain Capital, Mr Romney makes an unlikely defender of the poor and the working class. But President Obama and the Democrats face a handicap familiar to Labor in Australia in the wake of the global economic crisis. To defend his economic stewardship, the President has to sell a negative: he must argue that the US economy would be in a far worse state if it had not been for the massive economic stimulus measures undertaken by his administration, and that the consequent swelling of public debt was an unavoidable, though still manageable, consequence of those measures. That argument is correct, but its truth does not make winning the votes of those who fear losing their jobs, or who have no jobs, any easier.

The President's vulnerability on the economy, and Mr Romney's highly assailable record in business and as a state governor, have so far denied either man a strong poll lead. An average of recent national opinion polls put Mr Obama just two points ahead. US presidential elections, however, are decided not by the popular vote but by winning a majority of the electoral college vote, which in practice means winning enough swing states. The crucial battles will be in Florida, North Carolina, Virginia, New Hampshire, Pennsylvania, Ohio, Iowa and Colorado, and at present the balance favours the President. Mr Obama could lose the key states of Florida and Ohio and still amass the 270 electoral college votes needed to win. But Mr Romney must win at least one of Ohio or Pennsylvania, and win back Florida, Indiana, North Carolina and Virginia, all of which swung to Mr Obama in 2008. If he cannot win Florida, he will not win the White House. But with 156 days to go, the balance may yet swing again; it's going to be a bumpy ride.

Protecting young heads

IN 2002, Essendon great James Hird underwent surgery for a head injury and, after eight weeks on the sidelines, returned to play wearing a helmet. A decade later, as Australian Rules increases in speed and ferocity, the matter of how best to protect footballers from serious injury is still being debated. Each season brings renewed discussion. Last year former Melbourne player Daniel Bell lodged a claim with the AFL Players Association after a neuropsychologist found his cognitive function had deteriorated significantly from concussions; this year Labor politician and former Carlton player Justin Madden offered to donate his brain to science to assist research into the long-term implications of concussion and serious head injuries.

With the AFL expected to announce a new approach to concussion testing in coming days, the question is whether it should go further than this. Should helmets be obligatory? Further research may be needed to determine the effectiveness of helmets at senior level - even with head protection US gridiron and hockey players suffer life-threatening brain injuries, but theirs are very different games. There is, however, little doubt that head protection is vital for junior players, whose brains are more vulnerable to trauma.

While the very young are protected by rules banning tackling and bumping, individual clubs are left to determine their own policy on helmets in junior teams (with players aged from about 9 to 17), despite lacking the safeguard of modified rules. About half these young players wear helmets, the rest perhaps discouraged from doing so for fear of not being seen as tough enough. They should have no choice. Regardless of what the AFL decides for senior teams, junior players need protection and compulsory helmets are integral to this.