WASHINGTON – Conservative activist Grover Norquist declared this week that increased immigration could serve as “a key driver of economic growth” in the nation’s future and dismissed claims contained in a report issued by the Heritage Foundation that welcoming workers beyond America’s borders would cost taxpayers trillions of dollars.

Norquist, president of Americans for Tax Reform, told the Joint Economic Committee that an immigration reform proposal circulating in the Senate likely would result in “an infusion of foreign-born workers to supplement our work force and allow our economy to continue to grow.”

“In addition to making us more competitive globally, immigration makes native-born Americans more prosperous,” Norquist told lawmakers. “American workers and immigrants have mostly different skill sets because immigrants are likely to have different levels of education than native-born Americans – on both the low and high ends of the skills distribution.”

As a result of those different skill sets, Norquist said, new immigrants and native-born residents generally don’t compete against each other in the job market, which would result in lower wages.

“The complementary relationship between immigrants and native-born workers increases overall production rather than fostering direct competition,” he said.

The hearing before the committee focusing on the economic benefits of immigration stands as a preliminary bout in the upcoming fight over immigration reform legislation, also known as the Border Security, Economic Opportunity, and Immigration Modernization Act, which gets its first consideration before the Senate Judiciary Committee on Thursday.

As proposed by a bipartisan group of senators known as the “Gang of Eight,” which includes Florida Republican Marco Rubio, considered a strong candidate for the 2016 GOP presidential nomination, the bill would provide legal status for the estimated 11 million undocumented immigrants currently residing in the U.S. although they would not be automatically eligible for citizenship. It also expands the opportunity for work visas for foreign workers and further strengthens border security.

The measure has drawn opposition from some conservatives who view it as an amnesty for undocumented workers. But Norquist argued that “people are an asset, not a liability” and that growth can only help the economy.

“By bringing millions of able workers out of the shadows, giving them access to greater employment opportunities, and requiring them to pay taxes, this legislation will spur economic growth,” he said. “By facilitating a larger flow of future immigrant labor, both low-skilled and high-skilled, it allows for a demand-driven, merit-based approach to immigration, while freeing up law enforcement to prosecute human traffickers, drug smugglers, and other criminals.”

It also, he said, “creates millions of new taxpayers who will help keep America on sound fiscal footing where demographics are not currently in our favor.”

Steven A. Camarota, director of research for the Center for Immigration Studies in Washington, D.C., was less enthusiastic, asserting that under-educated immigrants represent a drag on the economy.

“Immigration makes the U.S. economy larger,” he said. “However, by itself a larger economy is not a benefit to native-born Americans. Though the immigrants themselves benefit, there is no body of research indicating that immigration substantially increases the per capita…income of natives.”

Camarota also maintained immigrants create an additional cost to local government, stating that “there is general agreement that less-educated, lower-income immigrants are a net fiscal drain.” He also said they carry a dilatory effect on the employment prospects for native-born workers.

“Because the least educated and poorest Americans are the most likely to be in competition with immigrants, they tend to be the biggest losers from immigration,” he said.

Sen. Amy Klobuchar (D-Minn.), vice chair of the Joint Economic Committee, agreed that the legislation would enhance, rather than hinder, economic growth.