According the Emerson College Polling Society:

[Terry] McAuliffe's strongest area of support are in the north within Congressional district 8(75%-13%), district 11 (58%-32) and district 10 (52%-37%). Cuccinelli is winning all the other districts with his strongest support in district 7 at (49%to 27%)

That incredible 6-to-1 edge in the Eighth District is why McAuliffe leads every statewide poll in Virginia's gubernatorial contest yet still falls well short of actual majority support.  It is a particularly striking edge, because the district is largely white and affluent rather than poor and minority.  What makes it unusual is that a vast number of voters there work or the federal government, work for those who provide services to the federal government, or work for those who try to curry favor with the federal government. 

The Eighth District consists of the independent city of Alexandria, Arlington County, and parts of Fairfax County.  As can be seen here, Arlington County and Alexandria complete the 10-mile-by-10-mile square that was the original plan for the District of Columbia.  How it reverted to Virginia is quite a tale of pre-Civil War political maneuvering to protect slavery.

Today, if Virginia is turning blue, it is entirely because of the explosion of Democrat voters whose work is related to the federal government and who reside in the Virginia suburbs of Washington, D.C.  The partisan and cultural split in Virginia politics is such that if this area comes to dominate statewide politics, other residents of the Old Dominion state could very well start to beg, Take this county back, please.

The ink hadn't completely dried on the ratification of the Constitution by the last of the 13 original states when the deal-making began.  Treasury Secretary Alexander Hamilton wanted the federal government to assume the debts various states had incurred fighting the American Revolution, to be paid off with a series of federal duties and excise taxes.  Southern states were against this, in part because of the expansion of federal power and in part because powerful Virginia had already retired its own war debt.  Hamilton held a private dinner with Congressman James Madison and Hamilton's major political rival, Secretary of State Thomas Jefferson.  The deal hammered out was that the federal capital would be established on the Potomac River, on land donated by both Maryland and Virginia, in return for votes for Hamilton's financial plan.

In 1790, a 100-square-miles site was well beyond anyone's most optimistic growth projections.  To get a sense of how well beyond, consider that in 1790, the federal government was temporarily located in New York City.  The island of Manhattan today, after some extensive fill projects of the 19^th century, comprises a little less than 23 square miles.  In 1790, everything north of Canal Street was rural.  While codes limiting building height to maintain the U.S. Capitol's dominance of the skyline encourage sprawl, the spread of federal agencies and federal employees deep into Virginia and Maryland is certainly something that was never contemplated.  

In 1847, after several years of controversial haggling by Congress, the Virginia Assembly, and municipal citizens, the federal government let Virginia re-annex its share of the 1791 deal through the Retrocession of the District of Columbia.  An early decision had been made not to build government buildings on the Virginia side of the Potomac to avoid issues involving George Washington's ownership or control of many prime sites in the area.  That left the Virginia side with an ongoing economic disadvantage.

Like most political deals of the era, however, the 1847 move was deeply entwined with the volatile issue of slavery.  A growing abolition movement fueled calls to ban slavery, or at least the slave trade, inside the District of Columbia.  Alexandria had a busy slave market, and significant parts of rural Arlington County relied on slave labor.  (In 1850, the slave trade in the District of Columbia was, in fact, abolished in the misguided hope that the move might offset the inclusion of the notorious Fugitive Slave Act in the Compromise of 1850.)

In a closely related matter, abolitionist forces were growing in number in the Virginia Assembly.  Adding Arlington back to Virginia also added pro-slave seats to the Virginia Assembly, that, in turn, was seen as forestalling a major congressional headache.  An abolitionist majority in part of the Virginia Assembly could easily upset the carefully crafted balance between free and slave states that had become part and parcel of congressional debates over all new admissions to the Union.

The constitutionality of the controversial retrocession has never been determined.  On the surface, it certainly seems that the re-annexation by Virginia violates the Contract Clause of Article One, Section 10 of the U.S. Constitution.  Virginia had contracted to "forever cede[] and relinquish[]" that area to the federal government, and then Virginia re-annexed it.  The Constitution does not say that Congress has the power to waive the Contract Cause restrictions on a state's actions. 

This leads to tough questions.  If unconstitutional, what remedy might be considered, especially at a late date?  What if the federal government doesn't want the area back?  And what about those who live there who now have expectations of self-determination?  It is one thing for an individual to move to the District of Columbia with knowledge of the lack of a voting member of Congress.  It would be another to have D.C. move to engulf those who currently are represented in Congress. 

In some ways, the deep political split among Virginia voters today echoes the one that led to the bitter and ultimately fruitless compromises that caused the District of Columbia Retrocession -- and which also caused West Virginia to break away as a separate state at the start of the Civil War.  A progressive movement that once rallied the working poor over the evils of owing one's soul to debts at the company store today sells the exact opposite approach.  Subprime home loans; reckless borrowing to pay tuition toward college degrees that will not lead to well-paid jobs; buying votes from the lower class in return for free phones, EBT cards, and expanded Medicaid -- paid for by borrowed money.  The elite of the media/government complex promote policies that chain Americans.  The 21^st-century slave masters seek to bind future generations to a crushing obligation to pay down mountains of public and private debt before they can even contemplate marriage, home ownership, starting a family, and other components of the pursuit of happiness.

In a fascinating postscript, President Lincoln unsuccessfully tried to get Congress to re-annex the area when Virginia joined the Confederacy because portions of Arlington County provide ideal sites for artillery to besiege Washington, D.C.  This all led to perhaps one of the richest ironies in history.  The most commanding position on the Virginia side is Arlington Plantation, home of Confederate General Robert E. Lee and his wife, a descendent of Martha Custis Washington.  In May 1861, the federal government seized control of the Lee plantation.  In 1864, Union Quartermaster General Montgomery C. Meigs seized legal title to the property as well.  Then, because Meigs considered Lee a traitor, he also rendered the plantation house uninhabitable, lest Lee ever return.  Meigs did this by ordering the burial of numerous Union dead in the gardens immediately adjacent to the house -- the first dead to be interred in what became Arlington National Cemetery.

Lee's heirs had the last laugh.  At the end of a lengthy court battle, they won full compensation for the property.  The Courts ruled that the government can't seize property for the failure to pay a tax when the government itself set terms making it impossible to pay that tax.  (Shades of Obamacare?)  The law had been changed to demand that all taxes be paid in person by the owner of record.  No mail, no spouses, and no agents accepted.  Mrs. Lee's tender of funds was refused, and Lee himself would have been arrested on sight.

I suspect that the ghost of Robert E. Lee still smiles at such petty vindictiveness gone awry.  Meigs accidentally bestowed a honor unique among generals on Lee.  His beloved Arlington is now associated everywhere with military valor.  Not bad for the guy who was in command of the losing side.