Delaware Democratic Party | 371 followers on LinkedIn. The Delaware Democratic Party is the affiliate of the Democratic Party in the state of Delaware, headquartered in unincorporated New Castle County. The Delaware Democratic Party is one of the two biggest parties in the state of Delaware (the other being the Republican Party) and has existed since the Jacksonian Democrats broke away from the Federalists in 1825. Besides their most prominent current political figure, Vice President Joe Biden, the party has occupies all federal seats for the state in Congress and currently has majority control over the state legislative and executive branch.