I think you need to explain this. Two considerations:
1. In other countries, independent campaigns with little financial backing have had success. The need for very large amounts of money to win elections seems to be distinctive of the US.
2. The independents with such money are "independent" Lesters, in Lessig's terminology (i.e., they are people with enough money to influence elections). So you are using the word independent in a way that seems to show that you are not talking about the same problem.
An incumbent is already well known. People are willing to give them money and put them on TV because they are already a congressman. A challenger has to have enough money to be taken seriously or pay to get attention via ads etc.
I would search for some citations if I wasn't about to get noprocrasted out.
I think you need to explain this. Two considerations:
1. In other countries, independent campaigns with little financial backing have had success. The need for very large amounts of money to win elections seems to be distinctive of the US.
2. The independents with such money are "independent" Lesters, in Lessig's terminology (i.e., they are people with enough money to influence elections). So you are using the word independent in a way that seems to show that you are not talking about the same problem.