Trump heads into his convention in an unprecedented position

(CNN)First things first: The theme song of the week is Curb Your Enthusiasm. Poll of the week: A new ABC News/Washington Post poll finds former Vice President Joe Biden at 53% to President Donald Trump's 41% nationally among registered voters. Biden's advantage in the average of all polls puts Biden above 50% and ahead by around 9 points, depending on how you exactly average. What's the point: Trump enters the Republican National Convention in an unusual position for an incumbent: trailing. It's not just that he's trailing, though; he's trailing by a lot. If...