Protests that sprang up in Los Angeles over immigration enforcement raids and prompted President Donald Trump to mobilize National Guard troops and Marines have begun to spread across the country, with more planned into the weekend. From Seattle and Austin to Chicago and Washington, D.C., marchers have chanted slogans, carried signs against the Immigration and Customs Enforcement agency and snarled traffic through downtown avenues and outside federal offices. While many have been peaceful, some have resulted in clashes with law enforcement as officers made arrests and used chemical irritants to disperse crowds. Activists are planning more and even larger demonstrations...