Why are Senate races typically more competitive than House of Representatives races?

a. A single party rarely dominates an entire state, and gerrymandering cannot effect the statewide vote.
b. Higher campaign spending by incumbent House representatives leads to more one-sided races than in the Senate.
c. The issues debated in Senate campaigns tend to be more volatile than those that dominate House races.
d. Incumbent senators have little ability to pass legislation that will win them support from their constituents.
e. Senators have less latitude to depart from their party platforms, making it difficult to please their constituents.

Answer: a. A single party rarely dominates an entire state, and gerrymandering cannot effect the statewide vote.