Poizner, the state insurance commissioner, said he previously had concerns that the law encouraged racial profiling, but supports it now that Arizona Gov. Jan Brewer has approved some changes to the measure.
Poizner squared off against rival Meg Whitman, the former eBay Inc. chief executive, at the Tech Museum in San Jose.
Whitman and Poizner quickly took shots at each other. Poizner attacked Whitman repeatedly over her ties to Goldman Sachs, the embattled Wall Street firm that gave Whitman preferential access to stock offerings while she was head of the online auction house.
At the same, Whitman accused Poizner of flip-flopping in his positions on immigration, taxes and abortion.
Whitman, who opposes the new Arizona law, said Poizner's shift on it was "a classic case of Steve Poizner changing his mind. ... He has changed his position on virtually every single thing."
Poizner is trying to overcome a double-digit deficit in the race against Whitman ahead of the June 8 primary. The winner will face Democratic state Attorney General Jerry Brown.
