A previous effort failed in the 1980s when not enough states ratified the measure. Illinois is among 15 that have not done so. Supporters, such as Democratic Senator Heather Steans of Chicago, say it's important to press the issue until women achieve full equality.
"For those who claim that this is something just symbolic, I don't think there's anything symbolic about each one of us deciding how we cast our vote in favor -- for or against basic equality between men and women," says Steans.
Republican Senator Christine Radogno of Lemont voted yes, despite concerns about timing. She says it's an election-year attempt by Democrats to get women's support.
"I'm for the amendment, but frankly, I resent the fact that women are being used in this debate. We're being used as pawns from a pretty abysmal record going into an election year," says Radogno.
The measure, which needed a three-fifths majority, passed Thursday on a vote of 39 to 11. Six senators voted "present." It now moves to the Illinois House.