Rep. Mike Castle (R-Del.) will be running for Vice President Joe Biden's old Senate seat in Delaware, according to two GOP sources connected to the congressman, instantly giving Republicans the opportunity to flip a traditionally-Democratic seat in their column.
Castle will be making a formal announcement at noon in his hometown of Wilmington. Castle had been debating whether to run for higher office, or retire after serving nine terms in the House.
I'm honestly surprised that Castle, who's getting long in the tooth, agreed to fight for this four-year term. I'm also not used to Republicans actually having so much honest-to-God success in the recruiting department, but the NRSC has been on an absolute tear this year. Castle will be a formidable candidate for the GOP here; in all three polls that we've seen of this state in the past year, Castle has edged Democratic AG Beau Biden by anywhere from 5 to 21 points. That, combined with Castle's long statewide electoral track record, is enough for us to change our rating of this race from Safe D (RTW) to Tossup.