President Obama’s announcement Friday that he would stop the deportation of some 800,000 young illegal immigrants who were brought to this country by their parents isn’t likely to increase his share of the Latino vote much.

But there is still plenty for him to gain: turnout and enthusiasm in a community in which both are severely lacking.

Polling on the matter has long shown Obama taking about the same portion of the Latino vote as he did in the 2008 election — around two-thirds. And he will be hard-pressed to exceed that performance this year.

But even as his advantage has stayed largely the same, there were plenty of signs that Latinos may just stay home this year. Record deportations of illegal immigrants by the Obama administration and a lack of action on immigration reform have made Latinos much less enthusiastic about Obama.

A report from the Pew Hispanic Center in December, in fact, showed Obama’s approval rating among Latinos dropping to 49 percent, even as 68 percent said they still preferred him over Mitt Romney. Obama’s approval decline in this community has been bigger than in just about any other demographic group.

Similarly, a Latino Decisions poll conducted earlier this year showed 53 percent of Latinos said they were less enthusiastic about voting for Obama this year than in 2008, compared to 30 percent who were more enthusiastic.

That gap is particularly troubling for Obama given the fact that Latino turnout often lags behind that of other demographics. Despite the historic Latino support for Obama in 2008, America’s largest minority group still has big turnout problems, and it’s a distinct possibility that many Latinos will simply sit this one out.

Latino turnout reached new heights in both the 2008 and 2010 elections, but basically all of that increase was a result of population growth. Meanwhile, Latino leaders have struggled to turn out their increasingly powerful voter bloc.

As we noted last year, even as 16 percent of the nation is Latino and 10 percent of eligible voters are Latino, they comprised just 9 percent of the vote in 2008, and that number dropped to 7 percent in 2010.

In both years, Latino turnout lagged far behind both the white and African-American communities. While black turnout was 65 percent in 2008, Latino turnout was just 50 percent. Similarly, in 2010, black turnout was 44 percent, while Latino turnout was 31 percent.

In addition, Latino voter registration has dropped by 5 percent since the 2008 election. Some dropoff is normal after a presidential election, but the size of the decrease in Latino registration was bigger than at any point in the last four decades.

(Note: Much of that low turnout and drop in registration has to do with how young the Latino population is — i.e. very young. And young voters are notorious for staying home when unmotivated.)

In other words, there is a huge untapped resource out there for Obama. He tapped it to a large extent in the 2008 election, but there’s still plenty of motivating (tapping?) to do.

And initially at least, it looks as if his announcement Friday has done some good.

A new Latino Decisions poll of Hispanic voters in five key states (Arizona, Colorado, Florida, Nevada and Virginia) shows 49 percent say his announcement makes them more enthusiastic about him, versus 14 percent who say it makes them less enthusiastic.

Any polling done so closely to a major decision is likely to exaggerate the bump to some degree, but it’s certainly helpful for Obama (no less because Republicans are tripping over themselves in search of a response).

And as shown by his op-ed today in TIME Magazine pushing for the DREAM Act, it’s an effort that Obama intends to keep pushing.