“Now is the time to [reform immigration laws] so we can strengthen our economy.” So said President Barack Obama on Tuesday as he challenged Congress to give 11 million illegal residents of the United States a road map to citizenship.

“When you legalize those who are in the country illegally, it costs taxpayers millions of dollars, costs American workers thousands of jobs.” So said Representative Lamar Smith (R-Texas), senior member of the Judiciary Committee, earlier this week.

These statements contradict one another. One must be wrong.

Actually, both are.

There are powerful reasons to change the nation’s immigration rules, but economic necessity is not one of them. Yes, immigrants make a positive economic impact.  But little of the benefit, according to careful research, spills over to non-immigrant workers. The overall economy barely notices. Besides, there’s no evidence to suggest that illegal immigrants’ effect on the economy differs from that of legal immigrants.

Translation: The compelling reasons to reform our immigration rules involve politics, not economics. Therefore, Congress can amend immigration laws to fit our values and ambitions. It need not twist the rules out of fear of economic catastrophe.

Many of us picture immigrant workers in one of two ways ‑ both incorrect. Story No. 1: Illegal immigrants steal jobs from ordinary American workers. Inference: Let’s cut their numbers. Story No. 2: Immigrants – especially illegal immigrants ‑ work at jobs (agriculture, food preparation, construction, cleaning services) under conditions that American workers simply won’t accept. Inference: Let’s integrate illegal immigrants into the economic mainstream economy as quickly as possible.