Adding millions of workers through comprehensive immigration reform would have a devastating impact to an already poor economy, according to a growing number of Republicans in Congress.

Analyses of the Senate’s "Gang of Eight" bill show that the legislation would add 30 million additional immigrants to the United States over the next decade, at a time when the number of Americans not in the labor force has reached record highs.

"Granting amnesty to untold millions of illegal immigrants will flood our job markets and reduce wages and employment for those hard-working immigrants and lower-income workers who have followed our laws," Rep. Lou Barletta (R., Pa.) told the Washington Free Beacon.

One of the major reasons Rep. Walter Jones (R., N.C.) opposes the Senate bill is the impact it would have on the economy.

"Congressman Jones has consistently expressed his staunch opposition to the Senate bill—and any other legislation that provides a pathway to citizenship for illegal immigrants—for a variety of reasons, not the least of which is the fact that amnesty would allow individuals who have cheated the system and entered the country illegally to take jobs that could otherwise be filled by lawful citizens," his spokesperson Sarah Howard said.

"Congressman Jones believes that it is imperative that we secure our borders and not reward those who have broken our laws," she said.

According to the Economic Policy Institute, the unemployed far outstrip the number of available jobs in every major industry in the current economy.

For instance, in the retail industry there are over 1.2 million unemployed workers and only about 400,000 job openings. In construction, there are fewer than 200,000 job openings for the 1 million workers out of a job.

Experts say adding millions more to the labor force would harm working class Americans by taking away jobs and lowering wages. The Congressional Budget Office has estimated wages would decline by 0.1 percent in the first decade of the Gang of Eight bill.

Moreover, the Center for Immigration Studies found that the bill would add four times more guest workers than the reforms proposed in 2007. The number of temporary workers would increase by 1.6 million in the first year alone.

"First thing to keep in mind is it’s not a good time to push through anything even remotely resembling the Gang of Eight bill," said Peter Kirsanow, a member of the U.S. Commission on Civil Rights, in an interview. "Even in a roaring economy it would be a spectacularly bad idea."

"This is really bizarre," he said. "I don’t want to overstate the issue, but supposedly well-informed political leaders are doing something so blatantly boneheaded as introducing a bill that the net effect is going to increase immigration, both amnesty for 11 million and millions of guest workers, dramatically."

Sen. David Vitter (R., La.) said Americans in lower-skilled industries would be the hardest hit by a Gang of Eight type bill.

"I’ve been a strong opponent of the bill and the set of concepts from the very beginning, and one of my big concerns is that it would clearly push down wage rates in the U.S.," Vitter said in an interview. "And the folks it would hurt the most are lower skilled, less educated workers who are really, really struggling now as it is."

"I think this is, at this point, very, very well documented," he said.

Vitter pointed to the work of George Borjas, a Harvard economist, who has found that illegal immigration reduces American wages by roughly $100 billion a year.

"I think it’s very clear this is going to take an already tough situation and make it significantly worse," Vitter said. "And it would affect folks across the spectrum of jobs and incomes, but clearly the ones worst hit would be lower skilled, less educated workers."

President Barack Obama is attempting to bring immigration reform to the forefront, meeting with top CEOs this week in an attempt to persuade House Republicans to take up comprehensive reforms. Last week, President Obama met with Sen. John McCain (R., Ariz.), a member of the Gang of Eight and supporter of past amnesty bills, to "plot strategy" for passing a Senate-like bill.

It is not likely the House will take up immigration reform this year, though Republicans are working on a piecemeal approach to deal with issues such as border security and a version of the DREAM Act.

Vitter cautioned the House against passing legislation that could be used to go to conference committee with the Senate bill.

"I’m very hopeful the House will never take up the Gang of Eight bill, per se, and then if that’s true from my perspective the next big danger is they would take up some set of bills that would still lead to a sort of Gang of Eight conference committee," he said. "I think we have to be very careful about that."

"I do favor a targeted, step-by-step approach," Vitter said. "Let’s focus on enforcement first, and get that done in important ways, not just promise it for the twentieth time."

Kirsanow also warned against believing the promises of border security in exchange for amnesty.

"I would simply refer anyone to the Secure Fence Act of 2006," he said. "We were told that the border was going to be secured with a 700-mile fence. And here we are seven years later and we’ve got 30-some miles of fence."

Any promises of border security in the Gang of Eight bill, Kirsanow said, is contingent of the Obama administration’s willingness to enforce them.

"That’s the cartoon strip with Charlie Brown, Lucy, and the football," he said.