(Portland, OR)  --  The Portland Police Bureau is gearing up for today's May Day protests.  Multiple demonstrations are expected downtown as well as at Holladay Park and in the South Waterfront area.  The police bureau says they'll have a law enforcement presence on-hand near the demonstrations as needed.  Previous May Day protests in Portland have been marked by vandalism and clashes between opposing political groups.  In 2017, police arrested more than two-dozen people after protests erupted into a riot.