Americans are deeply divided over President Obama's decision to act on immigration reform through executive authority but are opposed to a congressional fight that could shut down the federal government, according to a new poll released Tuesday morning.

The Quinnipiac survey shows that 45 percent of voters agree with the president's decision to act independently on immigration while 48 percent say he should not have done so. The same poll shows the president's approval is underwater, 39 percent approval to 54 percent disapproval.

The president last week announced his intention to shield up to 5 million undocumented immigrants in the United States from deportation, a measure that the administration has categorized as necessary because of a lack of progress on the issue in Congress. The president's critics, meanwhile, have charged that the announced measures fall outside the scope of his authority and are unconstitutional.

Not surprisingly, support for the president's action is largely split along party lines. Seventy-four percent of Democrats say they support Obama's use of executive authority on the issue while 75 percent of Republicans are opposed. A majority of independent voters are against the action, 51 percent to 40 percent. There's also a generational split at play, with 59 percent of young voters between the ages of 18 and 29 saying they support the president's decision to act without Congress.

But although Americans are ambivalent about the use of executive authority itself, they remain opposed to a government shutdown over the issue. The poll shows that 68 percent of voters are opposed to a shutdown, including a plurality of Republicans — GOP voters oppose a shutdown 47 percent to 44 percent.

Obama will travel to Chicago on Tuesday to promote his administration's steps on the issue.

The telephone survey of 1,623 registered voters was conducted by land lines and cellphones between Nov. 18 and Nov. 23. The margin of error is plus or minus 2.4 percentage points.