The very smart and ever reasonable Megan McArdle explains why the so-called Emerging Democratic Majority is far from a sure thing.

2. Ethnic coalitions are inherently unstable.  It used to be a sort of natural law that urban Catholics voted Democratic.  Then Reagan won them in huge numbers.  And--contra those who are saying that the GOP now has to move left--they didn't win by getting more liberal.  Rather, the Democrats got more liberal, on crime and bussing, and the white ethnics who felt victimized by these policies fled.  The more ethnic groups you have, the more likely it is that you will eventually find the goals of those ethnic groups in direct conflict.  And the Democrats sure do have a lot of groups.  

3.  We are heading for a showdown between public sector unions and taxpayers.  That's going to put Democrats in a very tough spot.  Those unions are the backbone of the Democratic political operation.   But their pensions are, in many places, simply not payable.  Thanks in part to the late 1990s stock market boom, and in part to really scandalously bad accounting standards, politicians made a lot of promises they didn't pay for.  Those promises now can't be shed in bankruptcy, and all of the possible deals--which including hiking taxes to "tax revolt" levels, or shafting all the younger public sector workers--are bad for Democrats.  

Bingo.

The GOP can fairly easily fix at least one big demographic problem; the Democrats advantage with Hispanic voters. Republicans can reach out to Hispanics by supporting reasonable immigration reform; amnesty for those who are here and then securing the border. Who better to lead that fight than emerging GOP star Sen. Marco Rubio.

Hispanics are natural conservatives; religious, hard-working, family-oriented, pro-life. Democrats and the Obama team exploited the harsh and stupid language of the law-and-order anti-immigrationists. But that's all that really separates this constituency from the GOP base. Over the next two years, if they are as smart as they think they are, Republicans will embrace an inclusive immigration reform law and with it gain a whole new slew of potential voters.

UPDATE: Micky Kaus disagrees.