Nationally, Democrats may not have decided who their presidential candidate is going to be yet, but that didn’t stop 500 party activists in Fairfax County from a rousing pep rally Sunday dedicated to turn Virginia “blue” this November.

The high-energy partisan event, the annual Jefferson-Jackson Dinner sold out for the first time in memory, was standing-room-only. It was held on the same day that word was getting out that Republican Presidential Candidate John McCain had opened his Virginia campaign headquarters in Pentagon City.

A Democratic presidential candidate has not carried Virginia, long considered solidly in the “red,” or GOP, column, since 1964. But all the numbers point to the fact that this November could break the streak.

The numbers also suggest the pivotal shift will be centered in Fairfax County, Virginia’s largest with over a million residents, which has exhibited a dramatic shift toward Democratic majorities in statewide elections since 2000.

Eastern Fairfax County, in the areas closest to the City of Falls Church and Arlington, is considered especially key. That area encompasses the 11^th Congressional District, where four Democrats are now vying for their party’s nomination in a June 10 primary to replace Rep. Tom Davis in the fall. The district has been named one of the three most likely in the U.S. to shift from Republican to Democratic control this year.

Davis helped buoy already-high spirits at the Democrats’ Jefferson-Jackson Dinner in McLean Sunday. His words about how bad things have become for the GOP were displayed on a large screen at the event. “The political atmosphere facing House Republicans this November is the worst since Watergate,” Davis wrote in a memo, displayed at the dinner, “and is far more toxic than the fall of 2006 when we lost 30 seats and our majority and came within a couple of percentage points of losing another 15 seats.”

Davis has also been quoted widely on the Internet saying, “If the Republican brand were dog food, they’d take it off the shelf.”

“Thank you, Congressman Davis,” Fairfax Democratic Party Chair Scott Surovell exclaimed gleefully from the podium, as the 500 activists at the Jefferson-Jackson dinner cheered Sunday.

Surovell, the young, enthusiastic new Democratic county chair, showed off an impressive power-point presentation to the audience demonstrating just how key Fairfax County will be to the Democrats’ chances, nationally, in November.

The county first demonstrated this in the narrow election of Democratic U.S. Senator James Webb in November 2006. Not only did the county tip the balance in Webb’s favor during the Democratic primary earlier that year, but its absentee ballots counted in the wee hours of the morning after the November 2006 race were decisive in giving Webb a narrow 9,329-vote win that tipped the balance to a Democratic majority in the U.S. Senate. Since it gave Webb an upset victory over GOP Incumbent Sen. George Allen, by torpedoing Allen’s political career, it likely also denied the Republicans their best presidential candidate for the 2008 election.

Webb’s margin over Allen, while 9,329 statewide, was by a whopping 64,723 in Fairfax County.

Citing five successive statewide elections since 2000, Surovell in his power point showed everyone there the unmistakable trend in Fairfax County voting patterns. In 2000, George Bush won Fairfax by 5,680 votes, but in 2001 Democratic gubernatorial candidate Mark Warner won Fairfax by a 25,738-vote margin. In 2004, Democratic presidential candidate John Kerry won Fairfax by a 33,691 margin, and in 2005, Democratic gubernatorial candidate Tim Kaine carried the county by a 60,382 margin. Then came 2006, when the margin for Sen. Webb was 64,723 in the county.

The reasons for the dramatic shift in voting patterns in the county, Surovell proposed, includes the unpopularity of George Bush and “the changing Northern Virginia workforce,” fueled by the growth of technology-based defense contracting industries.

“Tech workers are more diverse and higher educated,” Surovell noted. While the county was 81% white in 1990, it was only 67% white in 2006, with the growth of Asian and Hispanic populations being the most dramatic.

This better-educated, tech-savvy workforce also tends to be more progressive in its thinking, others such as George Mason University’s Dr. Richard Florida have noted. Florida coined the term, “the creative class,” to define this phenomenon, which has been the subject of two widely-acclaimed books.

Then Surovell went on to describe the impact of the Democrats’ “secret weapon” in the county, which included the activists in the room, as well as upgrades to the party’s organization and fundraising powers in the county. He did not let the fact that there is no Democratic presidential nominee to date deter the enthusiasm in the room. Referring to the fall presidential campaign, he proposed using the candidate name of “Hillack Obinton,” until a more definitive one is determined.

News of the opening of McCain’s state headquarters in Pentagon City, which was leaked onto the Internet last week, broke into the mainstream media on Tuesday. State GOP Chair John H. Hager noted that the office is being opened far earlier than the usual post-Labor Day timetable for a presidential campaign. It will be used not only to give McCain a jump-start in Virginia, but to boost the GOP changes in a number of Congressional races, as well.