After Reconstruction, the Republican Party thought it would own the votes of African-Americans -- forever. But in 1927, a deluge of rain turned the Mississippi River into "an angry dark ocean." Levees burst. Homes, crops and towns were washed away. Hundreds died. Tens of thousands fled for high ground.

Commerce Secretary Herbert Hoover organized the national flood relief effort. His quick and decisive action earned the eternal gratitude of many Southern voters -- but not all. Whites were rescued with alacrity. Black families were largely left to fend for themselves.

Some African-Americans were forced into squalid refugee camps. Once there, many were dragooned to rebuild levees -- sometimes at the point of a gun.

Hoover shrugged off the complaints of black leaders. However, when running for president the following year, he promised to aggressively address racial injustices in the South. He didn't.

And as Hoover sat in the Oval Office, thousands of African-Americans fled the South for "big city" jobs up North. When the 1932 presidential election rolled around, they backed the Democratic candidate, Franklin Delano Roosevelt. A great migration, political as well as geographic, was in full swing.

Is President Obama on the verge of sparking another big voting-bloc migration?

It his first presidential campaign, Mr. Obama promised Hispanic voters that he would "fix" immigration. That promise proved empty. For two years, he did nothing -- even though his fellow Democrats controlled both houses of Congress. He still hasn't introduced a bill of his own. Though he "adopted" the Development, Relief, and Education for Alien Minors Act (aka the Dream Act), he never mounted a serious push for it.

Right before the last election, Mr. Obama did issue an executive order allowing some alien minors to sign up for deferred deportation. But this "solution" merely dumps those who sign up into a legal limbo. Critics contended that the move was nakedly political.

Now, the White House is signaling that the president will make big promises for immigration reform in the State of the Union address. Details are curiously lacking. But reports suggest he will call for "comprehensive reform" -- Washingtonspeak for a bill that offers amnesty to the millions of people now living illegally in the United States.

"Comprehensive reform" has failed to find favor with either Democratic- or Republican-controlled Congresses since President Bush proposed it in 2007. Further, the White House has done virtually nothing to rally support or negotiate with leaders in Congress to improve the chances of passage. All this suggests that the president would be perfectly happy if immigration reform failed again. After all, he could just blame his failure on Republicans, further tightening his party's hold on the Hispanic voting bloc.

But in making such a calculation, Mr. Obama might risk overplaying his hand. As long as immigration reform remains a political plaything, people in this country illegally will remain consigned to the shadows, and those playing by the immigration rules will remain stuck in the waiting line. Meanwhile, employers won't be able to get the workers they need.

Somewhere along the line, Hispanics, reform proponents and industries interested in growing the economy may figure out they are being played.

And who knows? Conservatives may get their act together. They may offer a responsible way forward that secures our border, grows the economy, strengthens legal migration and offers fair and compassionate solutions for fixing our immigration mess.

If the president isn't careful, his cavalier and cynical approach to immigration may send Americans flooding in a different political direction.

-Examiner Columnist James Jay Carafano is vice president for Defense and Foreign Policy Studies at the Heritage Foundation.