- Swalwell leads in the polls, but his margin over Katie Porter and Tom Steyer is narrow enough that all three remain within the same competitive tier
- Steyer's massive self-funded ad campaign has driven a steady rise in the polls — though his favorability numbers haven't kept pace with his name recognition
- The prediction markets may have the right winner, but the degree of Swalwell’s advantage looks more decisive than the underlying data suggests
Prediction markets have a useful property that polls lack: traders have to back their opinions with money. That accountability tends to produce more honest probability estimates than a survey ever could. So when both Kalshi and Polymarket are pricing Eric Swalwell at roughly 60% to win the California governorship — far ahead of Tom Steyer or Katie Porter — it's worth taking seriously. It's also worth stress-testing.
As of this writing, Kalshi gives Swalwell a 59% chance of winning, followed by Matt Mahan at 13% and Tom Steyer at 12%. Polymarket tells a similar story: Swalwell at 61%, Steyer at 13%, and Mahan at 7%.
The message across both markets is the same. The question is whether the underlying data agrees.
At the Ballot Book, we've been tracking nearly every gubernatorial poll released this cycle through our polling aggregator. As of March 31, 2026, our model shows the following:
If you're a Democrat, the prospect of Republicans taking both top spots — locking Democrats out entirely — is probably the first thing that catches your eye. That scenario is worth its own analysis, and we've written about it previously; the short version is that it's probably less likely than it might appear here.
The more immediate question is which Democrat is leading the pack. Swalwell sits at 12.2%, followed closely by Katie Porter at 11.4% and Tom Steyer at 10.4%. Swalwell is technically in first, but the margins are narrow enough that all three remain tightly grouped at the top — separated from the rest of the field, but not decisively separated from each other in current support.
To get a better sense of where the race is heading, it helps to look at how these numbers have moved over time:
Since all three candidates officially entered the race last November, Swalwell has steadily held a lead in the low-to-mid teens while Porter has seen a modest decline. Steyer, by contrast, has climbed gradually from the low single digits to the mid-to-low teens.
It's been a slow enough rise that it would have been easy to miss — particularly for anyone who wrote him off based on where he started.
Whether that trajectory continues, however, will depend less on additional exposure and more on whether those new voters ultimately break in his favor.
But trends matter in a way that individual polls don't. A snapshot tells you where a candidate stands today; a trend tells you where they're headed. And a candidate who is still gaining ground months before the primary presents a different kind of risk than their current numbers alone suggest — particularly if that growth proves durable.
Steyer's rise is no accident. A look at Paul Mitchell's California Ads Transparency Project — which uses raw data to track and estimate candidate ad spending — makes clear why his numbers have been moving:
The figures aren't perfect — comprehensively tracking ad spend across every platform and market is an inherently difficult task — but they tell a clear story about just how lopsided the spending in this race has been.
And it may not be over. The Ballot Book's fundraising tracker shows Steyer has raised more than $100 million in total, nearly all of it from his own pocket, suggesting there's likely more media spend still in the pipeline:
The polling impact is hard to miss. The Berkeley IGS Poll from mid-March put it plainly, noting that Steyer has received "the largest increases in voter assessments over the past six months" of any candidate in the race — a direct result of his ad campaign. Before it launched, just 36% of voters had an opinion of him at all, and those who did viewed him unfavorably by a two-to-one margin. That recognition figure has since jumped to 66% of likely voters.
Awareness, though, is not the same as support. Steyer's spending has bought him a place in voters' minds — but at some point, the returns on additional ad spend start to diminish, and the question shifts from whether voters know who he is to whether they like him enough to vote for him. Converting name recognition into a winning coalition is a different challenge entirely.
The same Berkeley IGS poll offers a useful window into where that stands:
The numbers bear that out. All three leading Democrats are underwater on favorability with the electorate as a whole, but Steyer's imbalance is the most pronounced.
Among Democrats specifically — the voters who will actually decide the primary — Swalwell appears somewhat more consolidated than his rivals. He carries the highest favorability and the lowest unfavorability of the three, and still has room to grow. Steyer's spending has driven real awareness, but a meaningful share of that awareness has cut against him.
So what does all of this mean for the prediction markets?
The prediction markets are probably right that Swalwell is the current favorite — but the data doesn’t clearly support a price that makes him such a decisive favorite over Steyer or Porter.
There are understandable reasons traders have landed there. He's led among Democrats in the polls since entering the race, built the broader endorsement coalition — particularly among labor, where his backing runs deeper than Steyer's despite some significant union names on both sides — and his talent for drawing Trump's attention has been a political asset. That last point may get a fresh boost after FBI Director Kash Patel moved to release a years-old case file tied to Swalwell's past, a move Swalwell has already begun turning into a campaign moment.
But the race is more open than that price implies. Two Republicans are competing to consolidate the GOP vote while three Democrats are competing to do the same on their side — and that contest is genuinely unsettled. Swalwell's advantages are real, but so is Steyer's momentum, and the market hasn't fully reckoned with what happens if his favorability starts catching up to his name recognition.
That's not to say the market is wrong about Swalwell — it may well be right. The issue isn’t necessarily the direction — it’s how confident that advantage should be at this stage of the race. With months of spending still ahead and favorability numbers that have real room to move, Steyer remains the most important variable to watch — not because of where he stands today, but because of how much uncertainty still surrounds his ceiling. The race isn't over — it may not have even fully started yet.