Why do the Unions and Liberals try to make it sound as though Conservatives are against working families?

Union members represent a small portion of the work force and in the case of public Union members they rely on the taxpayer for their salary, health care and pension. Yet, when a struggling state Government tries to limit collective bargaining for these Unions in an attempt to cut costs they start screaming that Republicans and Conservatives are against the working man when it's the working man and the middle cl who has to pay for their bloated salaries and benefits. Why do they want to make sound as though Conservatives and Republicans are against the working man and the middle cl?