I'm not a fan of how these are plotted.

This could have three bar plots, with "Red States" and "Blue States" on the X-axis (y-axes the same). Error bars to indicate the variability across red or blue states. Actually, it would have been even better at the level of congressional districts, but I don't know if those data are readily available.

Also, Mann-Whitney U-Test instead of a t-test (unless you can demonstrate a normal distribution).