Mitt Romney finally clinched the Republican nomination on Tuesday by clearing the benchmark of 1,444 delegates. Even though polling day is more than five months away, the general election campaign has already been in full in swing for weeks with both campaigns running a litany of attack ads.

Barack Obama's campaign has focussed on Mitt Romney's career with the private equity firm Bain Capital arguing it acted like a vampire, sucking the life out of companies and destroying jobs.

And Romney's campaign has run equally tough adverts highlighting what they would deem the failures of the Obama presidency.