Elections Central: Comparing Senate Forecasts
JPM
"The Republicans have a 63% chance of winning the Senate." -New York Times
Republicans have a 48% chance of winning the Senate.- Five Thirty Eight
Polling provides a snapshot of the political climate in a state. Imprecise though it may be, news sources across the board have identified some key states that are running the closest races. They are: Nevada, Illinois, Indiana, Pennsylvania, North Carolina, and Florida.
You can see all 34 races and how some major news outlets are calling them below:
What states carry the most weight in the overall political scheme? According to FiveThirtyEight, using a "Tipping-Point Chance" metric (meaning, discerning the probability that a race will decide whether the Democrats or Republicans are in the majority), those states with the highest tipping-point chance are North Carolina (13.8%), Missouri (11.7%), Pennsylvania (11.13%), Nevada (11.1%), New Hampshire (11.0%). If we compare this assertion with the chart above, we can see that North Carolina, Pennsylvania, Nevada, and New Hampshire are states ranked as having "competitive races" or labeled as a "toss up."
Furthermore, the states ranked as having the "relative likelihood that an individual voter in a state will determine the majority party," or having the highest "voter power index" were New Hampshire (14.7%), Nevada (9.9%), Missouri (4.1%), Alaska (3.5%), and North Carolina (2.9%). These states are running some of the closest races.