Politico has an article out about how Obama has been laying the groundwork to isolate repub conservatives to the south. In Obama's most recent appointment, he nominated Rep. John McHugh (R-N.Y.) for Army secretary. The idea of nominating very qualified repubs from areas trending dem is not new.
"It’s an event that’s happening with enough frequency to suggest the presence of a design, a plan that not only sketches the outline of a reelection strategy but manages to drive a wedge into the opposition at the same time. Call it a Sherman’s March in reverse — an audacious attempt by Obama to burn down any lines of escape for Republicans from their one refuge of popularity, the deep South."
What is the strategy? Politico lists many. First, Obama keeps his campaign promise to be bipartisan. Second, and most interesting, is that by taking out moderate repubs he's isolating the conservatives in the GOP party to a regional southern party. (If you look, the GOP has been losing senate and house seats hand-over-fist in the North and Midwest over the 2 election cycles.)
Third, by taking away moderates from areas trending blue the GOP has to then spend serious cash in defending the seat. This takes away valuable cash that could be used to attack dem seats instead of defending currently held ones. This gives dems better opportunities.
Overall, its a great plan.