People really need to read the U.S. Constitution. It says, “All legislative Powers herein granted shall be vested in a Congress of the United States.”
The Constitution makes no reference whatever to executive orders (EO). George Washington started the practice mostly because he had to. Traditionally executive orders have been treated by Congress as having the legal status of legislation, but only insofar as they apply to the management of how the government operates.
The Constitution makes it quite clear that the President has no power to enact laws, but as long as an EO does not unilaterally alter or negate existing legislation or run counter to the Constitution Congress usually accords it legitimacy. Those that do not honor the separation of powers have been struck down by the courts or by legislation that opposed them.
As is widely rumored and reported, if President Obama does attempt to issue amnesty to illegal aliens he would be over-riding or altering existing immigration law. He does not have the power to do that.
Such an executive order would be immediately challenged in the courts and if power in the Senate passes to the Republicans in the midterm elections, Congress would oppose it. With an eye on the 2016 elections, incumbent Democrats might not be willing to go along with an Obama amnesty EO.
Recent polls all demonstrate opposition to amnesty. In a September Investors Business Daily/TIPP poll 73% of the public said that Obama should work with Congress on immigration reform. After the invasion of an estimated 150,000 young people and others from Guatemala and San Salvador earlier this year, comprehensive immigration reform went from 54% approval last year to 48%.