Given a chance to appear on national television and speak to the Republican National Convention, he said no. Gotta raise money, he said, and nobody listens to those speeches anyway. It may not have occurred to him that most of the money he's raising will go for more television time, so that he might as well have taken the free time offered at the convention. The point that Dorso drives home is that campaigning for the Congress these days is mostly about raising money. Day in, day out, members of the Congress raise money, and more money.
Challengers have to work twice as hard, or be twice as rich, to stand a chance.
To do so, all the candidates, incumbent or not, sell access to themselves. The candidates know that the people who come bearing checks from political action committees will be back. The next time it will be about pending legislation, or some other favor. And the campaign contributions will give the political action committee representative at least an edge. And that's enough.