A great time was had by California Democratic Party members at their convention last weekend in San Diego. Their party controls almost all the levers of power in California and will do so for the foreseeable future. Beginning with Gov. Jerry Brown, all 10 statewide elective offices are held by Democrats. That includes both U.S. Senate seats and the supposedly nonpartisan superintendent of public instruction, a post held by Democrat Tom Torlakson.

Democrats also hold nearly two-thirds majorities in both houses of the state Legislature. Thanks to redistricting, they well could claim two-thirds in the state Senate this November. And getting two-thirds of the seats in the Assembly might follow in 2014. Then they could pass tax increases without a single Republican vote. Thanks to Proposition 25, which voters passed in 2010, only a majority is needed in each house to pass a budget. So Democrats last year just ignored Republicans, except on taxes.

Republicans continue to debate how to get their mojo back in California. But for now, they have no solutions. That means Democrats should be held responsible for whatever happens in California, good or bad.

At their shindig, Democrats especially enthused about the tax increases they plan to put before voters in November. Gov. Jerry Brown touted his $7 billion tax increase measure, which would include a 2 percentage-point surtax on the incomes of the wealthy and a half-cent sales-tax increase for everybody. But he also worried about competing plans. For example, the tax-increase plan of activist lawyer Molly Munger, the daughter of billionaire Charles Munger, would impose an added $10 billion burden by increasing all income-tax rates by 1 percentage point.

The convention also saw a foreshadowing of a potential primary battle for governor. Attorney General Kamala Harris is appealing to the Democratic Party's radical wing. Lt. Gov. Gavin Newsom has tried to appear moderate by attempting to make end runs around Gov. Brown on jobs creation. But only in the Petri dish of Democratic politics could Mr. Newsom be considered "moderate."

Many observers assume that Gov. Brown, who will turn 75 in 2014, won't run again, but the quirky governor might decide to stay around another four years. Why retire when you're the life of the party?