A legislative supermajority is a fleeting thing, reports KQED's Sacramento Bureau Chief Scott Detrow:

Just a month-and-a-half into the new legislative session, California Democrats have lost the two-thirds majority they held in both the state Assembly and Senate. That’s due to the resignation of East Bakersfield Senator Michael Rubio, who is stepping down – effective immediately – to become a lobbyist for energy company Chevron.

Rubio’s resignation gives Democrats 26 Senate seats – one shy of two-thirds control of the 40-member chamber. (The party maintains a commanding 55-25 grip on the Assembly, and holds the governor’s office, too.)

The two-thirds hold on both houses was important, because California law requires a supermajority vote to raise taxes and put a new initiative on the ballot, as well as overturn gubernatorial vetoes. Assuming the parties vote in blocks, Senate Republicans now have the ability to put a hold on any proposed revenue increases.

Rubio’s resignation gives Democrats 26 seats in the 40-member chamber – one shy of a two-thirds hold. The party may regain its supermajority next month, when primary elections are held for seats vacated by Los Angeles Democrat Gloria Negrete McLeod and San Diego Democrat Juan Vargas, who both stepped town to become members of Congress. (If a primary candidates wins more than 50 percent of the vote, he or she is declared the winner and no general election is held.)

A special election for Rubio’s seat will be held later this year, 126 to 140 days after Governor Jerry Brown calls for one. That puts the timing into late June, right when legislators will be voting on this year’s budget plan.

Looking at the district’s demographics, analyst Allan Hoffenbloom says Democrats should be able to retain the seat. “Currently the Democratic registration is at 50 percent,” he said. “and the Republican registration is down to 28 percent. So this is a district, though in the past competitive, which will certainly favor a Democrat.” Hoffenbloom edits the “California District Target,” which assesses legislative elections.

In an announcement on his website, Rubio suggests that working as manager of California government affairs for the oil company will demand a lot less of his time than being a state senator.

"I have missed too many family dinner, bedtime stories and parent-teacher conferences," he wrote, noting that he has two daughters, one of them with special needs.

Rubio decided a year ago not to run for U.S. Congress because of his family's needs, he said.

The announcement caused an immediate flurry on Twitter as pundits tried to figure out the political implications:

With two Senate vacancies already, Rubio's resignation and another senator leaving for LA City Council, Senate supermajority falls short

— Daniel R. Walters (@WaltersBee) February 22, 2013

A complication for Dems on 2/3 supermajority & #CEQA reform backers, in state Sen. Michael Rubio's immediate resignation today

— John Myers (@johnmyers) February 22, 2013

The Sacramento Bee offers this background:

Rubio, who was elected to the state Senate in 2010, dropped plans to run for Congress in 2012 after his daughter was diagnosed with Down syndrome. One of the upper house's most moderate members, Rubio was leading a push to overhaul the California Environmental Quality Act. He was named chair of the Environmental Quality Committee last year and has worked closely with Senate President Pro Tem Darrell Steinberg on drafting legislation for the upcoming session.

Michael RubioMichael Rubio

Democrats Lose Supermajority in California Senate