About 400 people marched from a park in South Portland to the U.S. Immigration and Customs Enforcement building to protest the possibility of National Guard troops being deployed in the city. Federal agents arrested at least four people as the protesters neared the facility located in a residential neighborhood just a block away from the Willamette River. It wasn’t immediately clear who those arrested were or why they were taken. The protest started with a rally at Elizabeth Caruthers Park at noon, then protesters marched several blocks to the federal facility. As protesters rallied and marched, a helicopter repeatedly made...