One possibility is that the jet streams that normally hit the west coast straight on will instead swingup into Alaska and dive down the coast, bringing along cold arctic winds with it.
Warren White of the Scripps Institution of Oceanography in La Jolla, California, and his colleagues were the first to find that sea-surface temperatures across the globe swingup and down in a 10-to 12-year period that lags behind the solar cycle by two to three years.
One vital weapon in his arsenal was President Clinton who, like Vice President Biden, crisscrossed the swing States right up till Election Day to secure every possible vote in a tight electoral race.