Secretary of State of Kansas
The ruling by a federal appeals court panel dealt a blow to efforts by Republicans in several states to enact restrictive voting laws.
Her victory over a key ally of the president comes two years after the state overwhelmingly voted for Donald Trump.
In an unofficial tally, Kobach's office said his opponent got 100 fewer votes than county officials said he did.
The Trump supporter has made a name for himself with anti-immigrant views and allegations of voter fraud. Will Republicans make him their pick for governor?
The judge said the law championed by the Kansas Secretary of State Kris Kobach violated federal law and the 14th Amendment.
The ACLU's efforts to undermine experts who believe voter fraud is a substantial problem will have a lasting legacy.
The state official points to data showing 38 flagged names on one county's rolls in an 18-year period.
“This could really be in a lot of ways the case where we really put the evidence of fraud on trial in this country," said the ACLU's Dale Ho.