If you're seeking evidence that the Senate map is expanding, not contracting, for Democrats, look no further than Cook Political Report's ratings change in the Mississippi Senate race from "solid" to "likely" Republican. Republicans will most likely hold that seat on election night, but the idea that things are loosening even a tad in a state like Mississippi is somewhat astonishing. The movement in such an unlikely state also suggests Democrats are very much in the running to bring home some of the lower-tier Senate races.