California voters will decide Proposition 4 on the November 2026 ballot, a legislatively referred measure that would repeal the longstanding statewide ban on public campaign financing and permit state and local governments to create optional matching-fund or grant programs subject to spending limits and eligibility rules. Trader pricing favoring rejection at 58.5% reflects organized opposition from groups such as the California Taxpayers Association, which highlights the use of taxpayer dollars for political activity, combined with voters’ prior rejection of similar proposals. While reform organizations including the League of Women Voters and Common Cause have launched support efforts since early 2026, the absence of recent polling shifts or major endorsements has left implied probabilities anchored near historical base rates for campaign-finance ballot measures.