House Democratic leaders are expected to vote next week on legislation to grant statehood to Washington, D.C.. This comes after the House Oversight and Government Reform panel, in Feb, had approved the proposal, marking the first time a D.C. statehood bill had won committee passage since 1993. The House bill, though, has little chance of being considered in the GOP-controlled Senate.
Washington DC cannot be a state because the Federal Government cannot be under State Law. This is in keeping with the Supremacy Clause of the Constitution.