Supporters say it would make candidates campaign harder here in California.
The effort started after the 2000 election which George W. Bush won due to his electoral vote count even though more Americans voted for Al Gore.
The Assembly passed AB459 on Thursday on a 43-18 vote, sending it to the state Senate. The measure has supporters from both parties but drew only a handful of Republican votes.
The bill would take effect if it's approved by states with a total of 270 electoral votes, the minimum needed to elect president. Seven states with a combined 77 electoral votes have approved the move so far. California has 55 votes.
The Associated Press contributed to this report.