State Senate Democratic leaders were able to muster 21 votes, a bare majority, for the measure, handing a victory to Gov. Jerry Brown, a staunch supporter of the project who battled for weeks to counter criticisms over cost overruns. The Associated Press Friday evening reported that the vote was 21-16.

The bill passed by both the Assembly and the Senate includes $5.8 billion for construction in the Central Valley, as well as nearly $2 billion to improve regional rail systems in both metropolitan Los Angeles and the San Francisco Bay Area, overlapping them with high speed rail in what some pro-HSR voices categorize as a "blended" system.

The bill authorizes the state to tap $2.6 billion in state bonding authority (totaling roughly $8.9 billion) for the project, to be matched by $3.2 billion in federal funds. Federal officials, including Transportation Secretary Ray LaHood, had warned the state it might forfeit the federal share if it did not  approve state contributions.

Many opponents in the Senate, mostly Republican, have argued that the state's fiscal crisis makes any investment in high speed rail questionable; they also have cited recent polls suggesting the project has fallen out of favor with state voters, and suggest that the matter should be revisited in a public referendum. Supporters of the project have questioned the neutrality and relevance of the questions offered in some of those polls.