Swalwell defeated 40-year incumbent Pete Stark with an unusual coalition for this area: moderate voters new to a redrawn district and and insurgent Tea Party movement gaining traction in Contra Costa County and the Tri-Valley.

The upset stunned the East Bay and infuriated much of the Alameda County Democratic establishment, which viewed Stark as a progressive icon.

[...]

As Corbett prepared her campaign, Swalwell recognized the threat she posed. Local Democrats remained wary of him, labor groups were uncommitted, and his base looked much like the fragile coalition that carried him in 2012.

—Swalwell responded with an unconventional move: he sought help from the Alameda County Republican Party.

[...]

Sue Caro, then chair of the Alameda County GOP, later said she quietly met with Swalwell and a local party insider named Hugh Bussell.

The plan was straightforward: Bussell would run as the sole Republican, consolidating GOP voters and disaffected moderates—particularly in the Tri-Valley—to edge Corbett out of the top two.

—It worked. Bussell finished second in the primary, defeating Corbett by just 430 votes and abruptly ending her congressional bid. The outcome effectively secured Swalwell’s seat and ushered in a reluctant acceptance across the East Bay that he was there to stay.

That acceptance hardened after 2015, when the rise of Donald Trump prompted Swalwell to recast himself as one of Trump’s most outspoken Democratic critics. He became a near-constant presence on cable news—a role that defines his national image today.

But that transformation came at a cost. For the moderates, mainstream Republicans, and Tea Party voters who helped elect him in his first two campaigns, Swalwell’s pivot felt less like evolution than betrayal.

The over-reliance on being simply “anti-Trump” means most voters, including in his own district, have very little knowledge about where Swalwell stands on the issues.