Since the 1960's, the United States has shifted from a party centered campaign to candidate centered campaigns. The use of media has allowed individuals to become more familiar with individual personalities who speak directly to the people than with parties which have been associated with previous historical conundrums such as Watergate or Vietnam.
Typically, the Democrats appeal to Hispanics, African Americans, Millenials, women, blue-collar workers, or LGBT. The Republicans are often associated with white, older, elite populations though Donald Trump challenged this assertion through his support from the blue-collar workers.
The McGovern-Fraser Commission brought about these changes through its influence on ensuring women, minorities, and younger voters were represented at conventions and thus more likely to vote.
Parties created super-delegates with the the purpose of giving more independence to elites, super-delegates are not required to to serve any specific duty for the state primaries. They may be members of Congress, governors, or mayors.
Parties also form demographic coalitions through supporting specific policy ideas such as abortion laws, same-sex marriage, DACA discussions, gun ownership, climate change, and taxes.
Party Realignments occur when electoral forces change in regard to party identification. Typically these alignments are reflected in critical elections and have occurred 5 times in U.S. history. Typically party realignments are caused by:
First Alignment:
Second Alignment:
Third Alignment:
Fourth Alignment:
The Democratic Party also saw a shift in the 1960's following the passage of the Civil Rights Act of 1964. This led many former Democrats to join the Republican party. The Deep South would soon become aligned with the GOP rather than the Democrats as it once had been. Other issues such as busing public school children to deal with racial imbalances in schools and legalizing abortion led to conservative democrats shifting to GOP.
The 1960's and 1970's also a dealignment as people shifted away from politics and became independents. Voter turnout dropped, party loyalty decreased, and tickets were often split. A divided government became much more common than it previously had been with Congress not always being reflected as the same party as the President.