On the Fabian website today pollster Peter Kellner argues that the reverse Bradley effect could apply to the US election results if groups of people who have never voted before turn out.
In polling, as in so much else, the United States does not do things by halves, he argues. Kellner has just come back from visiting the YouGov offices in California and suggests that pollsters may be currently missing the curve.
The Bradley effect has been discussed in detail for months, but the reverse Bradley - which has the sound of an American football manoeuvre - is less obvious.
The argument, in summary, is that the polls may be missing groups such as young people and black Americans who have previously had a low turnout at national elections.
One thing is for sure, the Democrats would rather no-one yelled about this too loudly in case those much vaunted new voters don't turn out on the day, if they think they just aren't needed.