A bill that would shift the dates of Maryland’s presidential and gubernatorial primaries is headed to Gov. Martin O’Malley (D).

(By James A. Parcell/The Washington Post)

In 2008, Maryland, Virginia and the District all held primaries Feb. 12, creating a Potomac Primary that gave the region greater importance in the competitive race. That was undone by the national party rules effecting early nominating contests in the 2012 presidential cycle.

The legislation, which O’Malley sponsored, also would move Maryland’s gubernatorial primary from the second Tuesday in September to the last Tuesday in June.

The change is partly a response to a federal law passed in 2009 designed to ensure that military and overseas voters have sufficient time to receive absentee ballots and participate in elections.

Moving the primary to June in gubernatorial years would be a major change in Maryland politics — effectively extending the general election campaign by a few months.

The House passed the identical bill last month.