Three years after releasing a draft bill that didn’t get traction, U.S. Sen. Thom Tillis took another step forward Wednesday on patent law’s most contentious issue.

Tillis introduced legislation that would rewrite the law of patent eligibility and overrule Supreme Court decisions that have transformed eligibility into a tool for ending patent infringement suits early and at relatively little expense. Critics have complained bitterly that the Supreme Court decisions are so unprincipled that it’s difficult to know what’s eligible and what isn’t.