A lobbying arms race between Kalshi, Polymarket and the casino and gaming sectors is unfolding in Washington, with all sides vying to win over lawmakers amid increasing scrutiny of prediction markets from Congress and regulators. Kalshi's lobbying spending totaled $990,000 during the first half of 2026, according to filings this week, and nearly $1.8 million when including outside firms it's hired. That's more than the total $1 million the company spent on lobbying for the entirety of 2025 and marks the highest six-month spending to date for the company.

But the gambling and casino industry, which is fighting the rise of prediction markets, is also spending more on Capitol Hill. The American Gaming Association, a gambling industry group, spent $1.39 million so far in 2026 on lobbying efforts, pacing ahead of what it spent in 2025. When including outside firms, the group has spent nearly $1.8 million on federal lobbying, 30% more than it spent in the first half of 2025.

Cherokee Nation — which has casinos and other gaming interests — has spent $600,000 in the first half of 2026, also pacing ahead of its 2025 spending. A firm that lobbies on behalf of Kalshi's chief rival, Polymarket, has spent $180,000 on its client in the first half of 2026, a figure that puts it on pace to match the $360,000 spent in 2025. Polymarket's footprint on Capitol Hill is smaller than that of Kalshi's.

The former uses just one firm lobbying, while the latter has seven including its in-house firm. Prediction markets have been mired in political controversy since the start of the year, after a series of trades were made ahead of U.S. military actions in Venezuela and in Iran that raised concerns about insider trading.

In the last week, The Wall Street Journal reported about betting that may have been based on inside political information, while a teleprompter operator for President Donald Trump was suspended after it was disclosed he was under investigation for using material, nonpublic information to place trades on Kalshi. While Kalshi and Polymarket both say they have taken steps to root out insider trading on their platforms, lawmakers have also publicly expressed concern about bets placed on things like sports, elections and other government actions. Skepticism on Capitol Hill Kalshi has gone on offense on Capitol Hill.

The company has hired former Biden and Obama administration officials to aid its government relations efforts and counts Donald Trump Jr. as a paid advisor. CEO Tarek Mansour recently spoke at the Capitol alongside Democratic Rep.

Josh Gottheimer, D-N.J., in support of a bill aimed at protecting kids from online gambling. Still, prediction markets say they face an uphill battle when it comes to getting lawmakers' attention. That's due in part to the fact that the casino and gambling industry has had a head start, according to Patrick McHenry, a former Republican congressman who is now senior advisor to the industry group Coalition for Prediction Markets — which represents five companies, including Kalshi.

"So much of the existing infrastructure of engagement on the Hill and at the states has been by the casino industry," he said in an interview.