Re the 'old American family' comments; bear in mind that I don't have intimate knowledge of the UK class system.
'Technically' the US never had a nobility or aristocracy. We're all supposed to be seen as equal. So saying 'comes from an old American Family' probably doesn't mean the same thing as in the UK where I assume saying 'Old British Family' may carry the implication that the family is 'landed gentry' or titled. Here it just means that your family has been here a long time and money has nothing to do with it. One part of my family has been here since the 1600s, so it's just as proper to say that I come from 'an old American family' (of no particular money) as it is to say it of a wealthy family that's been here the same length of time.
Just out of curiosity, my dad's family (his grandparents emigrated in the late 1800s) has been traced back to the 1400s in a particular area of Cornwall. They're a line of miners, farmers, small businessmen. Wouldn't it be correct to say that their current descendants living in the UK 'come from an old British Cornish family' or is that description reserved for 'upper class' families?
I can understand a politician not wanting to say proudly "I'm the great great great great grandson of the Earl of Shitshire who polished the boots of Charles II" if he wants to appeal to the masses, but is just being of a 'posh' family really enough to put a politician beyond the pale with the average person?