In his article, “Analysis: If Obama Wins, Thank Latino Voters,” at ABC News/Univision web page, TDS Founding Editor Ruy Teixeira explains why Latinos are such a pivotal constituency in this election:

…President Barack Obama looks set to surpass his 2008 performance among Latinos (67-31 or a margin of 36 points). An average of the last eight national polls of Latinos has him ahead by 70-22, a margin of 48 points. The final Latino Decisions tracking poll released Monday shows Obama with a 73-24 percent lead among Latinos, with Obama’s share being the largest ever for a presidential candidate. This strong support from Latinos seems likely to drive Obama’s overall support level among minorities this year close to the 80-percent level he received in 2008.
As for turnout, there will be 23.7 million eligible Hispanic voters this year, an increase of 22 percent over 2008. This has brought the Hispanic share of all eligible voters up to 11 percent, 1.5 percentage points higher than 2008. Recent data also indicates that Hispanic voter enthusiasm, after flagging early in the campaign, is now, if anything, higher than in 2008. This data suggests that the Latino share of voters in 2012 should go up relative to 2008, helping drive up the overall share of minority voters in the process.
…If the minority vote share in 2012 merely matches its 26 percent share in 2008, then Romney needs a 22-point margin among whites (better than any Republican candidate since Ronald Reagan) just to nose out Obama by two-tenths of a percentage point in the popular vote. And Obama likely will win the popular vote if he can get just 39 percent of the white vote (he got 43 percent in 2008).
But Latinos should help drive the minority vote even higher than its 2008 level. If the minority vote were to exceed expectations and reach 28 percent, Romney would need a 25-point margin among whites to prevail in the popular vote. He has been nowhere close to that level in polling during this campaign.

Teixeira goes on to explain why it’s not just the advantage Latinos provide for Obama nationwide; It’s also the powerful edger Hispanic voters provide in three key battlegound states:

…The first is Colorado, where the Hispanic share of eligible voters increased by about four percentage points to 15 percent of eligible voters, accounting for all the increase in the minority share of eligible voters in the state in the last four years. Colorado is extremely tight, with Obama leading the race by less than a percentage point, so victory for Obama probably depends on his campaign’s ability to mobilize this burgeoning population of Hispanic voters, who lean heavily to Obama, according to the polls.
The second is Nevada, where the state’s gain in the share of Latino eligible voters was essentially the same as Colorado’s, taking the overall Hispanic share of eligible voters up to 17 percent. But in Nevada, gains among other minorities–blacks, Asians and those of other race–were also strong. Indeed, between 2008 and 2012, the overall minority share of eligible voters increased by an astonishing nine points, more than two points a year. Minorities are now almost 40 percent of Nevada’s eligible voters. But within that group, Hispanics loom large, being the biggest component of the minority vote and currently favoring Obama by large margins. They are probably the key reason why Obama’s average lead in the state is now three points and he is a currently favored to take the state.
The third state is Florida. Florida had roughly a two-point growth in the share of Hispanic eligible voters between 2008 and 2012, taking the overall Hispanic share up to 18 percent, with growth driven by increases among relatively liberal non-Cuban Hispanics in the state. Another two-point increase was contributed by growth among African American, Asian and other race-eligible voters, making for a total four-point increase in the overall minority share of eligible voters. If Obama has any chance of taking the state (he is currently behind Romney by less than a percentage point), it will be due to mobilization of minority voters, especially the fast-growing Hispanic population.

Democrats have a lot to be grateful for in 2012. But President Obama’s embrace of the Latino community, along with the GOP’s Latino-bashing, may top the list.