Story highlights Called "A Day Without Latinos and Immigrants in Wisconsin," the protests center on two pieces of legislation

Madison police estimated nearly 14,000 people gathered in the capitol by early Thursday afternoon

(CNN) Thousands of activists and allies poured into Madison, Wisconsin, on Thursday as part of a massive rally against legislation that protest leaders described as "racist" and "anti-immigrant."

to prevent local government from issuing ID cards to undocumented immigrants. Called "A Day Without Latinos and Immigrants in Wisconsin," the protests center on two pieces of legislation -- one, AB 450 , would ban so-called "sanctuary cities" in Wisconsin, while another, SB 533 , seeksto prevent local government from issuing ID cards to undocumented immigrants.

AB 450 recently passed the Assembly and is now expected to be considered by the upper chamber, while SB 533 has been approved by both and is headed to the desk of Republican Gov. Scott Walker. The governor's office did not immediately respond to an email asking if he plans to sign it into law.

Voces de la Frontera, one of the organizing groups, touted on its website "work stoppages, business closures and student walk-outs" in support of a broader effort to kill the bills and make a showing of immigrant economic power.

The author of AB 450, State Rep. John Spiros, a Marshfield Republican, rejected the characterization of his bill as "anti-immigrant," telling CNN he wrote it in response to the high-profile shooting death last summer of Kate Steinle. The 32-year-old San Francisco woman was allegedly killed by Juan Francisco Lopez-Sanchez, an undocumented immigrant and felon who had repeatedly re-entered the country after multiple deportations.

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