There is a large problem with lobbying in the United States but the influence they exert would be worse if there was no system. The efforts of interest groups would be exerted upon one candidate from each party, whereas Primaries make it harder for interest groups and 527’s to gain access to power as there are multiple hurdles for their candidate to overcome to win power and gain influence over policy. Primaries can also prevent capture of entire parties by interest groups as can happen in countries where funding of candidates comes directly from the central party such as the United Kingdom (where the role Trade Unions for example have 50% of the vote in the labour party conference [1] ). Candidate discretion is more likely in Primary systems, giving more choice over what the general election candidate will support as opposed to just following the lead of the party leadership, which causes more disillusionment to politics in the long run.  [1] ‘Ed Miliband ‘plans to water down trade unions’ influence over labour’’, The Telegraph, 3 August 2011,