Dealignment, in political science, is a trend or process whereby a large portion of the electorate abandons its previous partisan (political party) affiliation, without developing a new one to replace it. It is contrasted with political realignment.
Many scholars argue that the trends in elections in the United States over the last several decades are best characterized as dealignment. It is also believed the United Kingdom has become dealigned from social class over the past three decades.
The last decades, since the 1970s, have seen an increase in the process of partisan dealignment in many countries as voters become less connected to their political party. This process can result in fewer votes for the major parties, such as in the UK, or an increase in voters that vote for the opposite party due to their loss of partisanship. This dealignment shows that short term factors might play a larger role than usual in whether a candidate receives a vote from someone of their party. Several factors can be attributed to partisan dealignment, such as a greater political awareness and socialisation, intensive mass media coverage and decline of deference; disillusionment both with parties and politicians, and most importantly, the poor performance of government. Voters have also become more inclined to vote based on specific issues such as Brexit, immigration or the economy rather than voting based on a partisan attachment.
Partisanship dealignment has been clear in the UK as the Labour and Conservative Parties would previously gain over 90% of the vote between them, however in recent years this has decreased such as in 2010 when they only gained 65% of the vote, voters have lost their partisan attachment.
Class dealignment is a situation where members of a social class stop aligning themselves in terms of class and believe that they no longer belong to a certain class. An example of this would be if the working class began to view themselves as lower middle class.
Class dealignment took place in Britain post-1960s, when people were more likely to pursue tertiary education, have professional jobs and consequently more affluence. As a result, working-class voters who would traditionally have voted Labour may instead vote Conservative or Liberal Democrat. This happens as people lose their traditional class loyalties to a particular party. An example of this would be the Barking and Dagenham results in the 2006 local elections, in which a traditional Labour area voted for the extreme-right British National Party.