Can Harris burnish her presidential hopes in the rust belt?

Of all the lessons Kamala Harris's campaign will have learned from Hillary Clinton's botched run for president eight years ago, among the most important is that it's better to talk about jobs than guns in the three rust belt states that hold the key to the White House.

- Chris McGreal

The peculiarities of the electoral college will almost certainly see November's presidential election decided by voters in just seven states. FourArizona, Nevada, North Carolina and Georgia - lie in the southern sun belt.

But it is the three to the north - the rust belt states of Michigan, Pennsylvania and Wisconsin - that Democratic strategists are focused on. They are, in many ways, the real battleground within the battleground.

Shortly before Joe Biden dropped out the presidential race last month, his campaign team wrote a memo laying out victory in the rust belt swing states as the "clearest pathway" to defeating Donald Trump.

If Harris, the Democratic presidential nominee, can win the "blue wall" alongside the states that can be relied on to support her, that should deliver the 270 electoral college votes required to take the White House - whatever the outcome in the sun belt. But while some of the early signs are good for Harris, the rust belt can be tricky electoral ground, as Clinton found.