Following an interview with IBI in which National Marine Manufacturers Association (NMMA) president Thom Dammrich said legal immigration is key to filling job shortages in the marine industry, NBC News reports the Trump Administration is proposing policies that would make it more difficult for legal immigrants to get green cards (permanent residence status) or become citizens.

“If you look at the next decade and the number of baby boomers that are retiring, we’re not replacing ourselves fast enough, so we need a system that allows the population to grow through legal immigration,” Dammrich said Tuesday.

The NBC report cites the number of open jobs in the US at 6.6 million, with the number of unemployed in this country at 6.3 million. “Most economists would say we are at full unemployment,” Dammrich told IBI. “This may not be popular among some, but the only way to grow [the workforce] is through legal immigration.”

According to NBC News, the new proposal could impact some 20 million immigrants that are living and working legally in the US.