They kind of do. That is because even though a party is strong nationwide or within a state, there are high chances that their votes will almost be irrelevant because the votes will go to one of the major 2 parties. This system can discourage them from participating.
I think it's brainstorming
When a seat becomes vacant in the Senate it is filled by a special election, usually by a primary. When a seat becomes vacant in the House it is filled by primary election, nominating petition or party action, depending on the state law.
It has encouraged more than 3 times the amount of trade, and has done so by introducing multiple regional and bilateral free trade agreements.