Astate with a roughly equal number of democrats and republicans in the population is often referred to as a state.

It is often referred to as a battleground state. This term is derived from the US presidential election every four year. The battleground state has roughly equal number of democrats and republicans in the populate makes it unpredictable to which presidential candidate will be chosen by this State. Therefore, candidates usually pay more attention and resources to win the votes from the battleground states. Florida and Pennsylvania are two clear examples of battleground states.

What area are in blue

Where is the graph i don't see the graph