Final answer:
Candidates winning presidential nominations through primary elections largely do so independently, resulting in less obligation to the national party organization and enabling political outsiders.
Step-by-step explanation:
The consequence of the presidential nomination process in the United States, now that primary elections are used, is that candidates who win the nomination do so mainly on their own and owe little or nothing to the national party organization. This has been a result of a shift from a system where candidates were selected by party leaders at national conventions to a system where a sequence of state primaries and caucuses plays a decisive role. The primary and caucus system has led to a number of consequences, including the extension of the campaign season, increased costs, and enabling political outsiders to gain traction by appealing directly to primary voters rather than relying on the approval of party elites.