The Saginaw city council is expected to vote on an ordinance Monday that would give police more authority to break up large gatherings. But critics are concerned the ordinance could be invoked to stop peaceful protests, picket lines or even large family gatherings.(Steve Carmody / Michigan Public)On Monday, the Saginaw city council will consider an ordinance to crack down on large unruly gatherings. However, some city residents and civil liber…