Even though it is the middle of summer, and few voters are paying attention, you can be rest assured that whoever is running Claire McCaskill's reelection campaign is watching these polls.
The President is not popular in Missouri, and he's not going to win that state. McCaskill has tried to carry out her Senate duties as a centrist, and nobody's buying that. Replacing her with one of these nutjob Republicans is a non-starter; I refuse to be a purity troll and celebrate her being thrown out of the Senate.
But, here's reality for you--Missouri is going to send wingnuts to Congress, sooner rather than later. Might as well make them work for the seat.