How has partisan identification and voting behavior changed since the 1950s?

What will be an ideal response?

Party loyalty declined between 1950 and 1980, with less voters strongly identifying with a party, and those who did often voting for the other party. Increasing numbers of voters split their ticket between the two major parties. However, as white Southern Conservatives have sorted into the Republican parties, voters realigned and party attachment and loyalty grew. Today, few partisans defect from the party ticket for Congress and the presidency.