WASHINGTON -- When Sen. Bernie Sanders (I-Vt.) said this week that he opposes open borders -- more a hypothetical than an actual policy proposal -- no one was shocked. The Democratic presidential candidate supported comprehensive immigration reform in 2013 and favors a path to citizenship for undocumented immigrants, but he's long been skeptical of guest worker programs and other legal immigration that could squeeze out American workers. Some immigration advocates, however, said they were surprised Sanders quickly went from talking about open borders to saying he doesn't want immigrants to take American jobs.