DETAIL on lower-left corner of chart: Which states are doing best in controlling the Covid-19 outbreak? 

HOW TO READ: Of these states with relatively low number of new cases per week and a low growth rate (or, better yet, decline),  Massachusetts, Vermont, and New Hampshire are doing best of all.  

ANALYSIS: Note that all the Democratic-voting states are in the lower-left corner, with the exception of the four westernmost states (Oregon, Washington, Nevada, and California (not labeled unless you mouse over it; it's the large blue circle behind Georgia)).  Interestingly, the three swing states that flipped from Obama in '12 to Trump in '16 (shown in purple) are almost precisely in-between the Democratic states at lower left and the Republican states at upper right.  (Not shown: Hawaii (5 new cases per 100K pop. with 775% growth rate.))  "This week" means the seven-day period of June 6-19.  When hospital systems were starting to fail in Louisiana and the New York area in March and April, those states were seeing about 170 to 220 new cases per 100K pop. per week.
Chart: Kurt Hanson, CoronavirusWatch.com Source: CovidTracking.com Get the data