SPRINGFIELD — Rep. Michael J. Zalewski has taken up tough issues in the legislature before.He sponsored mandatory minimums for gun crimes to respond to violence in Chicago. He carried a bill to regulate the ride-sharing industry. He led a push to re-evaluate criminal laws in light of the state’s overcrowded prison system.But he probably hasn’t encountered anything quite like the push-back against his measure to regulate daily fantasy sports.“People are starting to throw things at me on the floor …