If there’s a must-read today for political junkies, it’s probably not the stating-the-obvious Balz-Rucker piece I just discussed, but Ron Brownstein’s analysis of Hispanic population growth and voter registration trends at National Journal. He begins by discussing the much-noticed slowdown and even reversal of immigration from Mexico, and notes that this won’t have much of an impact (unless it really intensifies) on the Hispanic percentage of the electorate until about 2050, if then.

The reason is that immigration is no longer the key to the growth of the Mexican-American population overall, and it is even less important to the rise of Hispanics in the electorate. As Pew calculated in 2011, new immigrants accounted for only a little over one-third of the 11.4 million increase in the Mexican-American population from 2000 to 2010. By contrast, Mexican-American children born in the U.S. represented 63 percent of the group’s growing population over that decade….

Brookings Institution demographer William H. Frey calculates that only about two-thirds of the 32.4 million Hispanics older than age 18 are citizens (and thus eligible to vote).

The story is very different, though, with the huge under-18 Hispanic population. Those young people represent over one-third of all Hispanics. And by Frey’s calculation, fully 93 percent of them are citizens. That means they are automatically eligible to register to vote once they turn 18. They don’t need to undertake the intermediate step of pursuing citizenship because they are American citizens by birth.

“The biggest gains in the Hispanic population are coming from young people who are now living here, are born here, and are now turning 18,” Frey says. “And that population is going to continue to shoot up…..”

How much will that population “shoot up”? Mark Hugo Lopez, the Pew Hispanic Center’s associate director, says that from 50,000 to 60,000 young Hispanics born in the U.S. now turn [18] “every month. And we will continue to see that pattern for the next 20 or 30 years.” Leaving aside any additional numbers provided by naturalization, that growth alone would increase the number of Hispanics eligible to vote by at least 600,000 annually for decades.

But in terms of Democrats who are counting on this steady growth in the Hispanic vote as a trump card (or at least as a counter-weight to a Republican “base” among high-participation older white voters), there’s a short-term “hiccup” that is worth watching closely in 2012:

The number of Hispanics registered to vote grew from 9.3 to 11.6 million from 2004 to 2008. But in 2010, Hispanic registrations declined to 10.9 million, according to Antonio Gonzalez, president of the William C. Velasquez Institute, which studies Hispanic political participation.

Gonzalez says that decline is most likely rooted in “the crushing weight of unemployment and home loss” that has compelled many Hispanics to move or otherwise disrupted their lives. “There’s musical chairs in the Hispanic community,” he says. “That’s crushing. None of us foresaw it. It should have occurred to us that there are political consequences to policy failure even in voter registration.”

At one point, Gonzalez predicted that 12 million Hispanics would vote in 2012, up from just under 10 million in 2008 and about 7.6 million in 2004. Now he thinks it unlikely to reach such a peak.

Indeed, some estimates are that the recent shortfalls in expected Hispanic voter registration growth could reduce the overall Hispanic vote by about a million from earlier, rosier projections. This is why voter registration drives among Hispanics in battleground states between now and election day could become a very big deal, even if Mitt Romney’s terrible record on issues of particular interest to Hispanic voters make it easy for Obama to match or even exceed his 2008 percentages in this demographic. And the stakes for Hispanics in showing their strength in 2012 go beyond the immedediate cycle, as Brownstein notes:

If Hispanic voters can’t impose an electoral price for the sort of aggressive policies that Romney has endorsed, the odds are high that more Republicans will also embrace them.

This is an important subset of the general proposition that an election which awards Republicans for the kind of behavior they have been exhibiting since 2008 will ensure more of the same in the future.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.