Today immigrants and worker rights advocates are marking the importance of immigrants to the US economy. During "A day without immigrants" thousands were expected to stay home from work and avoid shopping.The full impact of the action won't be known for a few days. .In theTwin Cities' Latino neighborhoods, stores were shuttered. While the day was meant to show immigrants' economic clout, the message may be more political than financial. Minnesota Public Radio's Marisa Helms reports.