AMERICAN POLITICAL HISTORY IS rife with presidential elections that were determined well before the year in which the campaigns were held.

The most prominent example in our lifetime may have been Jimmy Carter’s election in 1976 that likely was decided when his opponent, incumbent President Gerald Ford, pardoned his successor, the disgraced Richard Nixon, whose Watergate scandal brought down his presidency.

Four decades later, could that happen again? Has next year’s presidential election been determined by President Barack Obama’s broken promises for comprehensive immigration reform —  which has angered many immigration reform activists, including some threatening a boycott of the 2016 elections?

Could a low Hispanic voter turnout among traditionally Democratic-voting Latinos, caused by disappointment over the Obama failure to secure comprehensive immigration reform legislation, cost preemptive Democratic nominee Hillary Clinton the presidency?

There were renewed signs of that on Cinco de Mayo in Southern California when some Latinos — Union del Barrio-LA, MEXA de ELAC and the Los Angeles Brown Berets — protested Clinton’s appearance at a rally at East Los Angeles College.

“Organizers called Clinton an enemy of the working class,” LA Weekly reported. “They also argue that her Central American policies as secretary of state caused death, destruction and deportation.”

Last fall, members of a DREAMers’ organization confronted the former Secretary of State at a North Carolina rally over the Obama administration’s dismal record on immigration reform, raising the possibility that disillusioned young Latinos could threaten to urge the nation’s 25.2 million Hispanic voters to skip casting ballots in 2016.

Latinos boycotting the election would be payback for the foot-dragging by President Obama on immigration reform, which he promised in 2008 but has put off successfully championing in Congress and has only minimally executed through executive action.

Democrats in California today are still reeling from the likelihood that the notoriously low turnout among Hispanic voters in the 2014 off-year elections likely cost former Assembly Speaker John Perez the state controller’s election.

Perez, former Los Angeles Mayor Antonio Villaraigosa’s cousin, finished behind fellow Democrat Betty Yee by fewer than 500 votes, dampening the rising star dreams of the once politically powerful Perez, who had been a favorite to win the office.

Latinos make up more than one of every five registered voters — 22.7 percent — in California. But for Perez’s important statewide election they voted at a rate of just 6 percent.

Although Latinos historically have been low turnout voters, especially in mid-term elections, no one expected the dismally low turnout would cost Hispanics a statewide office and also raise questions about 2016, especially if immigration reform activists follow through on their boycott threat.

The reason for the President continually putting immigration reform on the backburner has been nothing short of playing politics. In 2014, Obama chose not to risk giving Republicans something more with which to rally their faithful in that mid-term year, fearing that the Democrats could lose control of the Senate in his final two years as president.

The GOP, however, captured the Senate anyway and, with control of the House of Representatives, virtually assured that the already sparse Obama legacy would have little more to showcase in his lame-duck years.

It has been theorized in recent years that not only could the ever-increasing Latino vote decide the next presidential election and those beyond, but it could shift the balance of power that will be felt negatively in 2016. A poor Latino turnout would effectively serve as a Hispanic voter boycott.

DREAMers and other immigration reform activists could potentially turn presidential politics on its ear.

“By mobilizing against Mrs. Clinton,” The New York Times reported last fall, “the self-named Dreamers hope to pressure her to commit to immigration change or risk losing critical Latino votes.”

Cristina Jimenez, managing director of United We Dream, the largest national network of young undocumented immigrants, was even more direct in threatening to launch a campaign urging withdrawal of support by the traditionally Democratic-voting Latinos from the 2016 Democratic ticket.

“If you’re going to pick politics over our families,” said Jimenez, “you should know that you can’t take this constituency for granted.”

This is especially critical for Clinton, considering that the Latino vote could potentially be even more important for her than it was for Obama.

In 2008, it was the overwhelming Latino vote that helped Clinton almost overtake Obama in their bitter Democratic primary battle for the nomination. That year, in Super Tuesday’s 16 primaries, Clinton carried 63 percent of the Hispanic vote compared with 35 percent for Obama.

The question now is whether Democrats will take the threat of a Latino boycott seriously.

It might do them well to acquaint themselves with what amounted to a similar Latino boycott in Texas in 1970, a time when Hispanic voters in the Lone Star State were proportionately the biggest Latino group in America.

Disillusioned with the Democratic Party, young Latino activists urged Hispanic voters not to vote in the 1970 election but instead to sign a petition to get the Chicano movement’s Raza Unida political party on the ballot for the 1972 election.

Texas state laws did not allow voters to both vote in the elections and sign the petition.

Ultimately, the Chicano activists succeeded in getting enough signatures from Latino voters to qualify La Raza Unida for the 1972 ballot. In doing so, though, the low turnout of Latino voters had an unintended historic impact.

U.S. Senator Ralph Yarborough, the incumbent darling of Texas progressives who was seeking re-election, was upset in the Democratic primary by businessman Lloyd Bentsen in a defeat that many liberals blamed on Chicano activists and their Latino voter boycott.

For Clinton, her potential problem with Latino voters is now compounded by statements she has made in the past while attempting to support the Obama administration’s decisions delaying immigration reform — as well as comments about the tens of thousands of Central American immigrant children who flooded across the border in 2014.

“I don’t think she had any idea of how that response was perceived by a young Dreamer who is thinking, ‘Um, we’ve elected a lot of Democrats,’” says Frank Sharry, executive director of the pro-immigration group America’s Voice.

“Immigration is not the only issue, but it is the defining issue, and she will need to learn that the old lines and old dynamics no longer apply.”