President Obama and his party have taken a huge political gamble on the issue of illegal immigration. It could turn a bad political year into a catastrophe.

Worse still for the president and his party, 2010 may sow seeds for future defeats.

Obama is resisting efforts to stop illegal immigration -- suing to block Arizona's crackdown and holding hostage federal enforcement of immigration law until Congress agrees to some sort of amnesty program for those already here.

The political calculation is that these stands, though generally unpopular, will fire up liberal voters and win the lasting loyalty of Hispanics, the kind that Democrats now take for granted with black voters.

The smart guys on Obama's political team crowed for months about playing base politics this year, pitting minorities and liberals against conservative, mostly white, voters in a battle of the bases.

By pushing a lefty agenda on issues like global warming and immigration, Democrats believe they will get their coalition to the polls despite deepening disappointment with Obama's policies.

It must have sounded good when they were pitching it around David Axelrod's office, but it has not survived contact with reality. Once again, the lucky breaks that led to Obama's 2008 victory have caused him and his team to overestimate their political gifts.

Democrats believe that their status as permanent majority is assured on the grounds that America will be a majority minority nation in the near future.

It is a dogmatic, often facile, belief that encourages Democrats to take big political risks.

But two, seemingly intractable problems threaten the Democrats' victory parade.

The first is high Republican voter intensity. A recent George Washington University poll showed Republicans with twice the advantage in voter enthusiasm they had in 1994. That might slacken a bit, but the overambitious Obama agenda and his poor execution guarantee that the GOP base will have the advantage this fall.

Second, and more perilous, is the collapse in independent support for the president and his party.

Remember that a one or two point advantage among independent voters can decide the outcome of a presidential election. Obama's big 2008 win was mostly achieved by winning independents by nine points, a margin not seen since Bill Clinton's 1996 re-election. Independents were a quarter of the vote in 1996 and are now about 40 percent of the electorate.

So it should induce screaming panic in the White House to see that the latest Gallup poll shows Obama with a 38 percent approval rating among independents. It was 56 percent a year ago.

The president can blame the oil spill, the stalled Afghan war, and the crumbling economic recovery for the drop, but immigration is in the mix too.

For middle-class voters -- the key bloc of independents -- immigration is both an economic issue and a security issue. The strong support for Arizona's tough law and calls for federal action cross ideological lines and reveal tremendous depth of feeling.

When they see low-wage illegal immigrants filling jobs and Mexican narco-anarchy spreading to the Southwest, swing voters, the kind who powered the electoral success of Clinton and Ronald Reagan, must wonder why Obama is so determined to be passive. It reinforces the impression that Obama and his party are out of touch.

The Democratic strategy of a base-versus-base election assumes that Democrats can hold their own with independents -- maybe not win, but at least compete. The Axelrod plan did not take into account the possibility of a 21-point swing from 2008 to 2010.

If Democrats proceed with their race-based strategy for eternal dominance they risk a defeat worse than any in a generation and also tremendous damage to their reputation on pocketbook and security issues.

The diverse Hispanic population in America will not be so loyal as black voters have been to the party since 1964.

Low-wage immigrants will give way to their middle-class children and grandchildren. And as we've seen with past immigrant waves, economic concerns eventually trump ethnic identity when it comes to political identification.

If Democrats pursue an irresponsible agenda now, they may have lost their best chance to establish themselves as a party of growth and prosperity.

Taking minority voters for granted and making politically cynical choices in this election year could be the start of a long, hard road for Democrats.

Chris Stirewalt is the political editor of The Washington Examiner. He can be reached at