Which way will Rust Belt vote?

The four states of Pennsylvania, Ohio, Indiana and Michigan between them account for 69 electoral votes, and are perhaps the main swing bloc in the country. In 2004, Ohio and Indiana voted for George Bush, while Michigan and Pennsylvania voted for John Kerry. Had Ohio, which voted for Bush by only a tiny margin, switched to the Democrats, John Kerry would have become president.

There are ways to win for either candidate without taking Rust Belt, but in practical terms, whoever takes the area in general, and Ohio in particular, will probably win the election. As a result, both candidates are investing heavily, with Barack Obama seeking to reverse the result in Ohio, and John McCain attempting to add Michigan into the Republican fold.

There are factors in all states that will benefit both candidates. All have seen major economic problems in the past few decades, generally blamed on outsourcing, and their workforces are heavily unionised. This should play into the Obama camp, with its pro-union, anti free-trade ideals. At the same time, the large number of veterans in those states, who have shown an overwhelming tendency to back McCain, means that both candidates will be able to make a fight of it.

However, in the primaries, neither candidate managed to get these states fully behind them. Obama lost the primary in all four states to Hillary (admittedly his name wasn't on the ballot in Michigan), and in the one seriously contested Rust Belt primary in the Republican race, in Michigan, Mitt Romney handily beat John McCain. As a result, neither candidate has managed to rally their base in these states.

In addition, a number of demographic problems loom for the candidates. Three of the states have fewer African-Americans than the national average (Michigan has more), and all are generally poorer than the national average, meaning that Obama's strongest supporters, Blacks and well-off liberals, are underrepresented. Similarly, much of the Republican support in the area comes from the rural populations of small-town evangelicals, whom McCain is still trying to bring on board. In this respect, both candidates are going to have to move beyond their traditional areas.

In this respect, the candidates' choice of running mates is interesting. Joe Biden is from a working class background, and still commutes from home to the Senate. Sarah Palin is a strong social conservative from a small-town background. Both have been clearly chosen to win over disaffected members of their respective parties, particularly in Rust Belt. Whoever does a better job, may well decide the outcome of the election.