What is partisan sorting?

What is partisan sorting? Why it is significant? Partisan sorting is an effect in politics in which voters sort themselves into parties that match their ideology. Partisan sorting is distinct from political polarization, which is where partisans subscribe to increasingly extreme positions. A partisan is a committed member of a political party or army. In multi-party systems, the term is used for persons who strongly support their party’s policies and are reluctant to compromise with political opponents.