pits newsom in another and more personal fight with trump, as california dives into the trump tax battle. >> federal government is not able for tors his hand, california will. >> reporter: state senator mike mcgwire introduced the bill and saying it's all about presidential transparency. >> if you're a democrat or a republican, you can choose not to release your tax forms, but you simply won't be on the california ballot. >> reporter: there's one person who vehemently resisted releasing his tax returns. >> we all know that's hog wash. >> reporter: four years trump has refused to budge. >> i would love to give them, but i'm not going to do it. it's very simple. >> reporter: to force trump hand's states are jumping in. this year, states introduced similar bills, california is expected to face legal challenges but democrats say they're not worried. >> this bill applies to all