blue wave

blue wave (plural blue waves)

1. (US politics) A surge of voters supporting the candidates of the Democratic Party during an election (especially a midterm election), which results in the party making significant gains.

   Coordinate term: red wave

   • 2013 June 23, Molly Ball, “Can Democrats Win Back the Deep South?”, in The Atlantic‎:

     A handful of local elections in Mississippi is hardly a blue wave. But Democrats across the South hope what just happened there is the start of something big – the first ripple of a Democratic comeback in the Deep South.