A top Illinois Democrat says pension boosts for public employees should require more support in the General Assembly before becoming law. House Speaker Michael Madigan is proposing a constitutional amendment to require a three-fifths vote of the House and Senate for any legislation that increases retirement benefits. A simple majority is required now. The state owes its pension systems $80 billion. The Legislature would have to approve the idea by May 6 to put the question before voters in the November election.