One of the unofficial purposes of the US Convention season is to give the finally nominated candidate a bit of a bounce in the polls. With his whole party united rapturously behind him, and the chance to make a prime time impacting keynote speech, there are few better, more unadulterated media opportunities for the presidential nominee. Pity poor Mitt Romney then. He entered the convention season neck and neck with a president who somehow has to explain why he deserves re-election while unemployment continues to rise. And the first post-convention tracker poll? The CNN-ORN poll puts President Obama some 6 points ahead now, with 59% of voters actually believing he will win, compared to a mere 37% for the hapless Republican.