Well, it’s Jerry Brown versus no one in the Democratic primary, but the yellow shirt he’s wearing for the ride to November has a bull’s-eye on it.

When San Francisco Mayor Gavin Newsom dropped out of the governor’s race Friday, he not only cleared the field for the attorney general, but also gave everyone on the GOP side seven extra months of free shots at Brown.

Sure, Republicans Tom Campbell, Steve Poizner and Meg Whitman will spend much of their time slapping each other around in an effort to convince GOP voters they have what it takes to run the state – and that their opponents don’t.

But while a non-stop intra-party mud fight tends to annoy voters and earnest discussions of public policy may bore them, a nasty attack on the other party’s likely nominee is a sure way to fire up the faithful.

With Newsom and Brown in the race, the GOP hopefuls might have held their fire, since they wouldn’t be anxious to give either man a leg up in the primary with the “If Republicans hate him, he must be the best candidate” argument. But with Brown out there by himself, there’s no need to hold back.

And Brown’s record provides a target-rich environment for Republicans. No one can spend 40 years in public life without taking sides on controversial issues, but the former governor has seemingly taken delight in starting many of those controversies in the first place.

Here are just a few of the names and phrases Republicans are likely to bring up between now and next November:

Rose Bird. “Small is beautiful.” Adriana Gianturco. “Era of limits.” Sidney Korshak. Oakland murder rate. Jacques Barzaghi. Highway construction. Linda Ronstadt. Same-sex marriage. Cruz Reynoso. Public employee unions. Governor Moonbeam. Prop. 13 flip-flop. Stewart Brand. Flat tax. Gray Davis. Presidential campaigns. Gary Snyder. Death penalty. Norman Hsu. 71-years-old. Tom Hayden

That’s only a start. When you’ve signed thousands of bills during eight years as governor, accepted campaign contributions from tens of thousands of people, companies and organizations and lived virtually your entire life in public, there’s guaranteed to be enough information out there to keep opposition researchers working overtime from now until election day.

On the other hand, there’s a reason the most recent Field Poll showed Brown leading every GOP contender by better than 20 percentage points in head-to-head matchups. And that Brown crushed Republican Chuck Poochigian 56 percent to 38 percent in the 2006 attorney general’s race. Or that Brown actually carried Orange County when he beat Republican Attorney General Evelle Younger when he was re-elected governor in 1978.

For years, Brown’s “canoe theory” of government has worked in California: “You paddle a little bit on the left, then you paddle a little bit on the right and you keep going straight down the middle.” He’s far from the only politician who’s tried to play to both ends of the political spectrum, but he’s one of the very few who has done it successfully over such a long career.

The crusading candidate for secretary of state in 1970 was very different from the pro-development, law-and-order Oakland mayoral hopeful of 1998, but both versions had something in common: they won.

John Wildermuth is a longtime writer on California politics.