Former Vermont Gov. Howard Dean announced last month that over the next two years his group Democracy for America will spend in state races with an eye toward building (or rebuilding) a Democratic advantage around the country.

"A little money goes a long way in these state legislative races," Dean noted. To that end, his group will spend $750,000 this year on behalf of five candidates for the Virginia House of Delegates.

It's hard to overstate how smart a way this is for liberal groups to invest their time and money. Virginia is a great case study for why state-level gains are key. Democrats control both of Virginia's U.S. Senate seats, and the state was key to President Barack Obama's victories in 2008 and 2012. Despite this, Republicans control all three statewide offices (governor, lieutenant governor and attorney general) and the House of Delegates, and they have the tie-breaking vote in the state Senate. The result? Republicans have had little difficulty pushing a strong conservative agenda in Virginia.