reporter: so why does arpaio have the right to ask people if they re illegal immigrants if that portion of the new law has not been allowed to take effect yet? it s a little known fact that dozens of counties, including maricopa county, arizona, have a partnership with the federal government that has permitted them to make those determinations. arpaio referrables in his reputation as a tough guy. i m turning off certain activists that don t like what i m doing. i m probably turning off some employers who hire illegal aliens for the cheap payment, money. so, i turn off some people. you know what? i serve the 4 million people that live here. reporter: on the day part of the new immigration law went into effect, arpaio and his department went on a crime sweep. deputies driving into the city s neighborhoods &. in this case, pulling over a mexican-american driver for a an expired registration tag. because he had a proper license, though, he was only ticketed, not taken into custody. t