Blue wall (United States)

The "blue wall" is a term coined in 2009 in the political culture of the United States to refer to the dozen-or-so states (along with Washington, D.C.) that consistently "voted blue" i.e. for the Democratic Party in the six consecutive presidential elections from 1992 to 2012. This trend suggested a fundamental dominance in presidential politics for the Democratic Party. Conversely, the terms "red wall" and "red sea" are less-commonly used to refer to states that Republicans consistently won in the same timeframe; states which have not voted consistently for one party are called "purple" or swing states.

During the 2016 presidential election, the Democratic candidate, Hillary Clinton, was considered a heavy favorite to win the electoral college because of this trend, but Republican nominee Donald Trump challenged the strength of the "blue wall" Rust Belt states of Michigan, Pennsylvania, and Wisconsin, which became swing states in the next three elections. The Trump victories in 2016 and 2024 included flipping these three states, and the 2020 Biden victory won all three states with lower than three percent margins.

The Southern United States had previously voted Democratic so reliably that it had been termed the "Solid South" until Republicans implemented the Southern strategy.