WASHINGTON — Sen. Chris Murphy is rolling out his measure to thwart foreign competition for military contracts and thereby help U.S. subcontractors in Connecticut and elsewhere compete for Pentagon business.

Murphy promised to introduce his BuyAmerican.gov Act last August, but hit a roadblock of practical politics on Capitol Hill: With Republicans in control of Congress, the bill was going nowhere without GOP senators as co-sponsors.

Now Murphy has two, Sens. Rob Portman of Ohio and Lindsey Graham of South Carolina. Also signing on is Sen. Sherrod Brown, D-Ohio. They unveiled the bill Tuesday.

Although Murphy has been a vociferous critic of President Donald Trump, the bill actually dovetails with Trump’s overall message of economic nationalism.

Early last year, Trump issued an executive order to beef up enforcement of military “buy America” regulations, which date back to before World War II.

“This is a major leap forward for manufacturing transparency,” Murphy said in an interview.

“Connecticut is peppered with companies that want to bid on contracts but are shut out by `buy America’ avoidance,” he said. “We didn’t have Republican buy-in but we’ve been working hard all year and finally have some interest.”

A factory powerhouse in the 19th Century and much of the 20th Century, Connecticut still boasts 4,600 manufacturers who account for 10 percent of jobs in the state and 87 percent of its total exports.

Although the Pentagon is supposed to give U.S. manufacturers first shot at contracts, the rules are easy to get around with very little accountability when the vast procurement bureaucracy proclaims critical parts and equipment are unavailable from domestic suppliers.

Since 2007, the Defense Department has spent around $200 billion on goods made by foreign companies. A DOD inspector general’s audit last year found the military’s main purchaser, the Defense Logistics Agency, failed to find available suppliers for 19 contracts —valued at $453.2 million — out of 32 contracts reviewed.

The main feature of Murphy’s measure is buyamerican.gov, intended to be an easy-to-search web site that lists all waivers to “Buy American” laws, as well as specific cases where the government is not using an American company.

Losing out on contracts is less of an issue for the big players like Sikorsky, Pratt and Whitney and Electric Boat than it is for smaller suppliers like The Platt Brothers and Company, a specialist in zinc products located in Waterbury.

For 15 years, Platt made the coating for conventional bombs being turned into smart bombs. Then in 2012, with little explanation, the Pentagon awarded the contract to European companies.

Platt won the contract back last year by slashing its bid, according to sales manager David Berardinelli.

“It makes me sick looking at it,” he said. “We’re losing money on the deal. We’re only doing it to make a statement.”

For Platt Brothers, which traces its Waterbury roots to 1797, the loss of military business has been “crippling,” Berardinelli said. The company employs 88 in Waterbury, down 20 to 30 percent over previous decades, he added.

Berardinelli blames predatory pricing by European competitors, as well as a wink-and-nod policy of U.S. government officials to prop them up.

“They were robbing Peter to pay Paul and, unfortunately, we were Peter,” he said.

Murphy said the Pentagon is under severe spending constraints, pushed to field the highest quality weaponry and equipment at bargain-basement prices. Buying overseas many times lets them cut corners without leaving fingerprints.

“It’s up to the White House to see the forest for the trees,” Murphy said. “The White House needs to see that every time to you squeeze the Pentagon, you lose American jobs.”