New Castle County executive Chris Coons announced Wednesday that he will seek the Senate seat formerly held by Vice President Joe Biden.
Coons was seen by many as the Democrats' fallback candidate after Biden's eldest son, attorney general Beau Biden, opted not to run for the Senate this year.
Coons is expected to face Republican Mike Castle, a former two-term governor who is currently Delaware's lone representative in the U.S. House, in November.
