History of Prior Proposed California Wealth Taxes

Opponents of California Proposition 40 (the Billionaire tax) try to scare voters that if Prop 40 passes, California legislators have a loophole that they may enact a tax to apply to all taxpayers.

California legislators can pass state-level tax laws without voter approval, provided they pass by a two-thirds supermajority vote in both houses of the Legislature (i.e. Assembly and Senate) and receive the Governor's signature.

Therefore, even if Proposition 40 does NOT pass, the legislature can try to pass similar legislation. 

Similar wealth taxes have been proposed by California and other states in recent years.

Since 2020, the California assembly has proposed 4 billionaire or wealth taxes [Assembly Bill (AB) 259, AB 2289, AB 310, and AB 2088] that all have failed plus one constitutional amendment that never reached voters.