PRESIDENT OBAMA has finally used powers well within his executive authority to shield from deportation — temporarily, at least — a potential 800,000 undocumented immigrants brought to this country as children.

No matter what you hear — and, in a nation plagued by partisan political mis- and dis-information, immigration issues typically top the list — the policy announced Friday by the Department of Homeland Security is not "amnesty." (After all, the reprieve does not apply to parents who chose to come to this country illegally, or overstay their visas, but only to children who had no say in the decision.) And the policy does not provide paths to citizenship: That would require Congress to pass the DREAM Act, legislation that began as a Republican idea but, despite wide popular support, has been blocked by Republicans (and a few Democrats) in recent years.

The new policy grants a two-year renewable reprieve from deportation — as well as work permits — for immigrants under 31 if they arrived in the United States before age 16, have lived in the United States for five years continuously, have a U.S. high-school diploma or GED or served in the U.S. armed forces, and haven't been convicted of crimes. If administered properly, this is huge.

Give credit to 2,000 young people who have bravely risked their futures to "come out" as undocumented in recent months and who speak for an estimated 800,000 people with similar stories who still live in the shadows.

One of the most famous is Jose Antonio Vargas, a former intern at the Daily News who revealed himself as an undocumented immigrant last year. Vargas, a native of the Philippines, wrote the cover story in last week's Time magazine that focused on the persistent myths about immigration — in particular, that there is some sort of legal immigration "line" that people like him can get into in order to get green cards. There is no process for Vargas and others to follow to get right with the law. (By the way, Vargas, now 31, is a year older than those who would be covered by the new policy.)

Besides the courage and passion of these young people, President Obama clearly is making a smart political calculation. The Latino community rightly has been dismayed at the fact that the Obama administration has deported a record 1.2 million undocumented immigrants in what appears to have been an attempt to mollify opponents of comprehensive immigration reform with the notion that they might be more inclined to support incremental measures like the DREAM Act. We have seen time and again how that approach has (not) worked out.

Although opponents charge that Obama abused his authority, the new policy is not an executive order bypassing Congress but a simple act of prosecutorial discretion. Law-enforcement agencies often make practical decisions on where to spend limited resources.

At the same time, Friday's move is nowhere near sufficient. For one thing, it could be reversed by a future president. True to form, Mitt Romney has refused to say whether he would.