Wisconsin Gov. Scott Walker has cracked down on protesters in the state’s Capitol building while issuing a new ultimatum to Democratic lawmakers. On Monday, demonstrators were barred from re-entering the Capitol, the site of 24-hour protests over the past week. Thousands of people have demonstrated and slept inside the building since Walker unveiled his plan to remove the collective bargaining rights of public workers. The American Civil Liberties Union of Wisconsin has protested the move, calling the barring of protesters during business hours unconstitutional. The Wisconsin State Employees Union and the Wisconsin Employer Relations Commission also filed an unfair labor practices complaint against Walker yesterday, alleging he failed to negotiate in good faith. While the Capitol building remained in lockdown, Walker issued another statement threatening to send layoff notices to 1,500 state workers unless Wisconsin Senate Democrats return to vote.