Gallup reports on party identification in the states:
There are similar numbers of states in each of the major categories, including 17 solid or leaning Democratic states, 15 that are solid or leaning Republican and 18 that are competitive. Those totals have been fairly consistent since 2011 -- but continue to mark a major shift away from the Democratic Party since 2008, the apex for Democratic strength nationally in the last 25 years. That year, Gallup classified 29 states as solidly Democratic and an additional six as leaning Democratic, to only five solid or leaning Republican.
