According to a report last month, the five richest states in the USA are Maryland, Alaska, New Jersey, Connecticut and Massachusetts whilst the five poorest states are Mississippi, West Virginia, Arkansas, Kentucky and Alabama. Politically, four of the five richest states (the exception is Alaska) are regarded as safe for Barack Obama and all five of the poorest states are regarded as safe for Mitt Romney.

Viewed from these shores, this is puzzling because the richest states are supporting the candidate of the left-wing party while the poorest states are voting for the candidate of the right-wing party. In England, if a constituency is prosperous you can be sure it does not have a Labour MP; very probably it will have a Tory MP and occasionally a Lib Dem. If a constituency is deprived, the Tories are glad if they save their deposit and the MP is invariably Labour.

A partial explanation for the prosperous citizens of a state like Maryland voting for a Democrat is that the centre of politics in the US is significantly to the right of the centre of politics in the UK and Europe. However, it is still the case that if you are earning very well you can expect to pay more tax under the Democrats.

Journalists often use the phrase “it’s the economy, stupid” when analysing elections and it is true that some people vote in elections on the basis of which party they think will make them and their family better off financially. It is ironic, as the phrase originated in the US, from Bill Clinton’s 1992 presidential election campaign, that this test is applied more by voters in the UK than those in America. In the US millions of votes are cast for non-economic reasons.

For the last few decades fierce debates have raged in America which have come to be known as “Culture Wars”. These cover a range of issues which are highly controversial in the US, such as the importance of religion, the law on abortion, gun-control and issues around homosexuality like gay marriage. Depressingly, even the issue of climate change, rather than being judged on the basis of scientific evidence, has become caught up in these Culture Wars. On these issues, the Democrats tend to have progressive, liberal views and the Republicans conservative, traditional views. For millions of Americans these issues are decisive.

Many of the poorest states in the US are in the Deep South. These states now vote solidly Republican in presidential elections. The vote is split on racial grounds. In 2008, Obama received some 98 per cent of the black vote in Mississippi and Alabama but was easily beaten by John McCain who received some 90 per cent of the white vote. The result was much the same when the Democrat candidate has been white.

Once it was the Democrats who were the beneficiary of white Southern voters as a result of the civil war and its aftermath. The states in the Deep South were slave states and they were defeated in the Civil War by a government led by Abraham Lincoln. Lincoln was a Republican, in fact the first Republican president.

After the Civil War and after Lincoln’s assassination it was the Republican Party that tried and failed to secure proper rights for the blacks in the Deep South. It was the Democrats who ensured that, although slavery was finished, the blacks in their states had minimal rights. Into the 1960s southern blacks faced discrimination, segregation and were denied the right to vote. Southern whites at the time never voted anything other than Democrat.

In 1964 it was a Democrat president, Lyndon Baines Johnson, who forced through the 1964 Civil Rights’ Act to make sure that blacks in the South could vote and had proper legal rights. He knew that this would earn his party the hatred of the white voters in the South. As he signed the law he reportedly said: “There goes the South for a generation.”

LBJ was right in that voters who had only ever voted Democrat now proceeded to only ever vote Republican. He was wrong about this voting pattern lasting “for a generation” – it has already been far longer than that.

The economy may well be the most important issue in the battle between Obama and Romney but it is by no means the only important issue.