GIVE THE VOTERS WHAT THEY ASK FOR, GOOD AND HARD: Democrats Poised for Complete Dominance in the West.

It is the stuff of liberal fantasies: a vast, defiant territory, sweeping along the country’s Pacific coastline, governed by Democrats and resisting President Trump at every turn.

A single election in a wealthy Seattle suburb on Tuesday could make that scenario a reality, handing the party full control of government in Washington State — and extinguishing Republicans’ last fragile claim on power on the West Coast. The region has been a rare Democratic stronghold on an electoral map now dominated by vast swaths of red, and Republicans’ only toehold on power there has been a one-seat majority in the Washington State Senate.

The prospect of such far-reaching autonomy for Democrats, who already hold all three governors’ offices as well as both houses of the legislatures in Oregon and California, has infused extraordinary energy into what might have been a low-key special election. The race is on track to draw more than $9 million in campaign spending, a record-breaking sum for Washington State. National environmental and abortion rights groups have mobilized, business associations and oil companies have poured in money, and a former vice president, Joseph R. Biden Jr., has intervened on the Democratic side.

Sharon Nelson, the Democratic leader in the Washington State Senate, conveyed the party’s grand aspirations in an almost Trump-like phrase: “A blue wall,” Ms. Nelson enthused, “from the Canadian border to the Mexican border.”

Leading in the polls and anticipating victory, Democrats have sketched an aggressive agenda on issues where strong consensus appears to exist in the party, including new laws on gun control, contraception and environmental regulation. Ms. Nelson said she had met with the speaker of the Oregon Statehouse about enacting policy across state lines. The three states’ Democratic governors have spoken regularly about policy collaboration, and over the summer began coordinated talks on climate change with foreign heads of state.

Let’s hope Kurt Schlichter is taking notes for another People’s Republic prequel.