Gov. Jerry Brown and Democrats in the Legislature took a major gamble this summer in approving a spending plan that depended on California voters raising taxes in November.

It was a gamble that paid off this week as, despite uncertain prospects going into Election Day, voters went along with the governor's plan by approving Proposition 30. Thousands of late mail-in ballots still must be counted, but the unofficial tally Wednesday had Proposition 30 winning by a margin of 54 percent to 46 percent.

Failure would have been devastating to K-12 schools, community college, state universities and UC campuses. They would have experienced a combined $6 billion in mid-year "trigger" cuts. The reductions for K-12 alone would have been equivalent to shortening the school year by 15 instructional days.

Instead, thanks to the efforts of voters and the hard work of Proposition 30 campaigners, most students will never feel the sting of those cuts. In some cases, college students will actually see a rebate.

The California State University system, for example, already raised tuition in anticipation of more budget cuts. Given the passage of Proposition 30, Sonoma State University President Ruben Armi?na said Wednesday that the CSU system will rescind the $249 per semester tuition increase.

The annual tuition for full-time undergraduate students, for example, will go back to $5,472, the rate it was during the 2011-12 academic year. Students will either be credited or refunded the difference in some way, Armi?na said.

Overall, this marks the first time that California voters have passed a statewide tax measure in eight years.

Tuesday's results also handed Democrats something of a surprise — supermajorities in both the state Assembly and the Senate. This means that Democrats can pass tax bills without Republican votes.

It's the first time since 1933 that either party has had two-thirds majorities in both houses of the Legislature. Democrats already hold every constitutional office decided by voters.

It will be a mixed blessing.

On that note, Brown pledged on Wednesday not to use his party's supermajorities to raise taxes more than when voters approved on Tuesday. In addition to passing Proposition 30, voters backed Proposition 39, which will raise an additional $1 billion a year for state programs by closing a corporate tax loophole.

Even with these funds, however, state lawmakers face possible budget shortfalls in the near term as well as major long-term challenges. The state Legislature late in the session took a first pass at pension reform. It was a good first step, but as we noted at the time, there's still much work to be done.

The new majorities also offer an opportunity for legislators to address the state's notoriously volatile tax structure and to ensure full funding for programs that have been turned over to local government, most notably incarceration of some felons.

It's also an opportunity to follow up on promises to review the state's environmental quality law, with an eye toward reforms that would discourage needless litigation.

Brown and the Democrats have reason to celebrate after Tuesday's election. But they can ill afford to underestimate the challenges that lie ahead. And if they fail to deliver, they will have no one to blame this time but themselves.