Lieutenant governor will succeed Gov. Terry McAuliffe
Danica Roem could become first trans state legislator
More than 200 people attended Crystal City event
Democratic sweep on Nov. 7 will send a message to Republicans across country
Jill Holtzman Vogel supports marriage, nondiscrimination bills
Transgender journalist running against Bob Marshall in Va.
McAuliffe, Northam and Herring will face off against anti-gay GOP ticket