In Congress, reforms democratized or 'opened up' selection procedures to broader participation. Senior members found themselves surrendering committee chairmanships to unknown newcomers. Whips found it harder to enforce party discipline and junior members increasingly pursued their own personal projects to gain media attention and impress their constituency voters. Congress members have much to gain, in publicity and in tangible rewards (grants for their constituencies) from unpredictable behavior.
The effect upon presidential influence in Congress has been destructive. President Carter struggled to pass bills through a House and Senate controlled by his own party. President Reagan's early successes were largely due to Democrat 'Boll Weevil' defections. President Clinton has likewise been unable to rely upon solid party support, particularly for his anti-crime legislation and Healthcare Reform bill. Congress has been split by the new individualism of its members.
The rise of the primary in presidential selection was another method used to 'open up' the political system and weaken party influence. Primaries allow voters a direct say in the choice of the party's standard bearer in the presidential election. However, they enable candidates to hijack the party nomination