IT may not be as catchy as "Yes We Can", but Barack Obama's message to the American people in these last few crucial hours of the presidential campaign is just as important: we have come too far to turn back now.

Many Americans have been disappointed with his record in office, and unmoved by his sometimes lacklustre campaign over the last few weeks, but that does not mean the choice is any less important this year than it was in 2008. The wrong decision in the US not only threatens to turn back some of the important reforms Mr Obama has introduced, it threatens to put America on a new path to social division.

Some of the disappointment with Mr Obama felt by Americans and supporters around the world is understandable. He said he would close down Guantanamo Bay. He didn't. He said he would cut America's debts. He hasn't. His strategy for economic recovery has also failed to significantly dent the high unemployment rate. It was the poor and the unemployed who helped get Mr Obama into power four years ago but for millions of them, things are just as they used to be.

But Mr Obama should be judged on his achievements as well as his failures. He promised reform on healthcare and he achieved it, meaning that millions of Americans can no longer be denied medical attention. He also said he would end the war in Iraq and he did pull US troops out; he has also largely succeeded in rehabilitating the US brand abroad, which was trashed so thoroughly by George Bush during his eight years in office.

Both of these achievements would be threatened by a victory for Mitt Romney. On healthcare, Mr Romney has said he would repeal the reforms even though they are similar to policies he himself introduced when governor of Massachusetts.

On foreign policy too, Mr Romney would be a potentially dangerous choice. He has promised more confrontational relationships with China and Iran and says he would send more of the navy ships he is so fond of to sensitive areas such as the Persian Gulf. He has made these promises largely because he has to pander to his increasingly extreme party. The danger is clear: if Mr Romney wins, the hawks could take to the air again.

To pay for all of this, Mr Romney says he would increase defence spending, a decision which goes to the heart of Republican economic policies that do not add up. Not only is Mr Romney committed to hugely increasing defence spending, he has also said he will cut taxes at a time when America needs all the money it can get. This could seriously threaten the slow but sure economic recovery.

We will find out in the next few hours whether any of these issues sway American voters, although the reality is that the result will come down to a few swing states and that most of America was never going to change its mind. Most of the old Confederate states of the South were always going to vote for Mr Romney; the old Union States would always go for Mr Obama. America is divided politically, socially, and economically, but a Republican who will cut taxes for the rich and reduce healthcare for the poor will only make the divide greater. For a country still in recovery, that is too great a risk.