From a Giants fan, it was the ultimate put-down.

"Racists are worse than the Dodgers," read 12-year-old Alex Skinner's black ink on blue sign.

Skinner and about 300 others marched outside AT&T park Saturday to protest Arizona's new immigration law and the arrival of the Arizona Diamondbacks.

The new law forces police making traffic stops to question people about their immigration status if they're suspected of being in the country illegally. It also makes it a state crime not to carry immigration papers. Critics say it amounts to racial profiling.

As Giants fans streamed in to see the game, protesters walked in a circle around Willie Mays Plaza, targeting their chants at Diamondbacks owner Ken Kendricks, who's donated to the Republican party and hasn't come out against the law. “Ken Kendricks you can't hide, we can see your racist side. You're busted. What what. Your busted. What what.”

"It's a way of saying of saying that everyone in Arizona should be responsible for what's going on in their state," said Alexis Parker, a first generation Salvadoran immigrant who's sign read "Swing and Miss for Arizona."

A Diamondback fan, who gave his name as Zach Funk, said he thought the protest was “silly.”

“What good is protesting a baseball team going to do?” he said outside the stadium. “They should go protest on the government steps in Arizona.”

Asked what he thought of the immigration law, Funk said “As I understand it Arizona is just enforcing a federal law so I guess the state decided that it was time to grow a pair.”

The rally was organized by the May Day 2010 coalition. They marched peacefully from Embarcadero BART to AT&T park. Cars honked in approval. Once at the stadium, Giants fans seemed generally supportive or unperturbed by the demonstration.

However, one fan swaggered through the marchers, yelling “You guys should find something better to do – This is a fucking baseball game.”

Sports teams have weighed into the debate on Arizona's law. The Phoenix Suns donned Los Suns jerseys during the playoffs and Baseball's players union with its many Latino players called on the state to repeal the law. And there have been calls to boycott the All-Star game, schedule to be played in Arizona next year.