From Starbucks to Microsoft, Grey’s Anatomy to grunge rock — Washington has always been a harbinger of trends. In this remarkable mid-term election, Democrats are spooked it may prove so again, delivering Republicans a vital Senate pick-up and potentially control of Congress.

Politically, Washington has a split personality. Republican strength is in the sparse rural eastern half, which votes like deep-red Idaho next door. Yet this is rarely sufficient to top the Democratic margin out of Seattle (where Barack Obama won 70% of the vote in 2008) and other urban centres such as Olympia and Tacoma.

So why in recent days has a parade of royalty traipsed through the state — and particularly hip, youthful Seattle —  to lift the struggling campaign of Patty Murray, Democratic incumbent here since 1992? Bill Clinton came first. Then Obama arrived to do a policy Q&A in a supporter’s backyard, followed by a trademark rally at the University of Washington campus — the sort of event that was so uplifting in 2008 yet in this vicious environment for Democrats, has taken on a battened-down, almost defiant quality. This week Michelle Obama hung out for a few days. Joe and Jill Biden have lent a hand. It all smacks slightly of panic. GOP candidate Dino Rossi put it best: “Well, if [Murray] was really doing that well, do you think the president would be here twice? The former president, vice-president, and the first lady?”.

The truth is, Democrats worry about turnout. Come back to this election’s basic maths. One, Republicans are super-energised. Two, Democrats are lethargic. Obama must resort to appearances with Jon Stewart because his progressive base in cities such as Seattle is disillusioned at his failure to meet expectations on issues ranging from Afghanistan to Guantanamo Bay to climate change to the repeal of “Don’t Ask, Don’t Tell”.

Three, independents (swinging voters) are breaking heavily Republican, driven by reservations about Obama’s health-care changes, high unemployment and agreement with the fiscal conservative message on deficit and debt. Independents are particularly important in states such as Washington where they comprise the largest share (roughly 40%) of the electorate. A state where independents are breaking towards the Democrats would be Delaware where the GOP candidate Christine O’Donnell is being laughed out of town (the latest poll has her down 21 points). By contrast, Rossi, with his credible background as a real estate executive and two narrow misses running for the governorship, has tapped into this year’s zeitgeist as well as anyone.

As the fourth-ranking Democrat in the Senate, Murray, would be a scalp for Republicans. Conscientious but low-key, the 60-year-old famously touts herself as an ordinary citizen politician or “mom in tennis shoes”. Rossi points out Murray has taken $666,000 in lobbyist contributions towards her re-election, the second-highest of all members of Congress. As always, there is plenty of pot calling kettle black, but it helps his central theme: that after 18 years of incumbency, Murray has “changed” — in effect, that she’s quietly upgraded her Dunlop Volleys to diamond-encrusted Nikes. For her part, Murray’s most pointed attacks accuse Rossi, a Roman Catholic, of wanting to “turn back the clock” on abortion, dusting off old votes he took as a state legislator to restrict health insurance coverage of contraceptives.

It’s hard to see a scenario where Republicans reclaim the Senate without Washington. Still, we could be sweating on a close result for a while. Washington votes by mail, a system that on its face gives an extra edge to the candidate whose supporters are most motivated and reside at stable addresses. Murray wins if she gets her supporters out — and she’ll need a big margin among women. But will all her college kids and urban 20-something slackers remember to lick the stamp and pop their ballot in time? The reason for her recent Dancing With The Stars routine with the Obamas becomes obvious: to keep the race in the headlines and voters’ envelopes on the breakfast table right next to their cereal and hemp milk.