The U.S. economy could shrink by as much as two percent if presumptive Republican nominee Donald Trump gets his wish of mass deporting millions of immigrants.

A new American Action Forum study also finds removing the estimated 6.8 million workers that would be part of that equation would trigger a drop of as much as $623.2 billion in private sector output.

Mass Deportations Could Create Worker Shortage

In addition, such action could leave millions of U.S. jobs unfilled, with such sectors as farming, construction and hospitality being especially hard hit.

"The things Donald Trump has said are utterly unworkable," said Douglas Holtz-Eakin, the forum's president and the top economic adviser to Sen. John McCain's, R-Ariz., 2008 presidential run.

Trump's hard-line stance on immigration is just one of several of his policy proposals that have raised eyebrows. He has also called for the dismantling of several international trade agreements and the construction of a massive wall along the Mexican border.

In taking his stance on immigration, Trump derided Mexicans by labeling them "rapists" and "drug dealers."

Trump Popularity With Latinos Still Falling

A recent Washington Post-Univision survey found that four out of every five Latinos now has a negative image of the political neophyte and New York City real estate mogul.

Researchers used data supplied by the Bureau of Labor Statistics to place an estimated value on the output of undocumented immigrants, arrived at the conclusion that such a mass exodus brought on by deportations would likely fuel a shortage of workers across various sectors.

According to the International Monetary Fund, the U.S. economy is projected to produce some $18.7 trillion worth of goods and services in 2016.

A recent Pew Research Hispanic study found immigrants now compose 13.2 percent of the U.S. population, compared to just 5.4 percent back in 1960.

Overall, the number of immigrants living in the U.S. has jumped from 9.7 million to 42.2 million over the last five decades. Hispanics are also now the youngest U.S. ethnic group, with roughly one-third, or 17.9 million, of the country's Hispanic population 18 or younger.