President Barack Obama called on Congress Thursday to finish work on an immigration overhaul by the end of the year, a lofty goal that will be difficult to meet given the staunch opposition of many House Republicans.

While immigration remains one of Obama's top second term priorities, the issue has been overshadowed for months, most recently by the 16-day partial government shutdown. The president's shift to a greater focus on immigration came as the White House was seeking to shift the conversation away from the deeply problematic rollout of Obama's health care law.