On Tuesday night, the Export-Import Bank became history as Congress lets its charter lapse, and with it a valuable prop that thousands of small businesses have depended on to guarantee their exports overseas.

Despite more than paying for itself--by its own reckoning, Ex-Im Bank has returned $7 billion to the U.S. Treasury in the last two decades through interest on guaranteed loans and credit insurance--the 80-year-old government-run financial institution is a sunset agency. That means its charter must be renewed periodically. And it has been 16 times over its lifetime, without much fuss.

Yet, on June 30, the bank appears to have been mothballed as Congress departed for its July 4th recess without reauthorizing the agency, leaving the fate of its 450 employees hanging in the balance.

Since 2012, however, the bank’s destiny has been uncertain as some conservative lawmakers have sought to make it an example of government waste and cronyism, in their own words. One of the chief gripes of the banks’ opponents is that it assists the exporting activities of very large companies such as Boeing, Caterpillar, and General Electric, which they say puts smaller companies at a disadvantage.

“Chairman [Jeb] Hensarling (R., Texas) has made it very clear he would like to let the bank expire,” Fred Hochberg, chairman and president of the Ex-Im Bank said during a recent sit-down with Inc.

In its activities, the Ex-Im Bank acts as a backstop for private banks, which might not otherwise want to take a risk on financing export trade deals, by guaranteeing loans to overseas customers who want to buy from U.S. companies. It also provides credit insurance to small companies in the U.S. who’d similarly like to sell to customers in other countries who might need more favorable purchasing terms than many small companies can offer.

Ex-Im's Pros and Cons

Although Hensarling, who chairs the House Financial Services Committee did not respond to a request for  comment, he has said the battle over the bank is one of philosophy, which for conservatives dictates that the government should stay out of free enterprise.

Here’s what Hensarling told Sheila Barr, former chairwoman of the Federal Deposit Insurance Corp., in a May interview in Fortune magazine:

“Relative to the size of your average agency in D.C., it’s pretty small, but it represents this Washington insider economy. It’s a small, boutique credit agency that primarily benefits Fortune 50 companies which can finance their own operations. GE or Boeing aren’t going to have a problem getting credit.”

That argument doesn’t make sense to Hochberg. While the agency is small, he concedes, it has a big influence on the economic life of the country. It supported 164,000 jobs and made 3,340 loans and other forms of financing to small businesses, generating a surplus of $675 million for the Department of Treasury in fiscal year 2014.

And the bank is not a lender of first resort for any company, large or small, Hochberg says. “Plan A is that we have a great private sector, with deep financial markets,” Hochberg says. “We are Plan B.”

As proof of its secondary importance, Hochberg says the Ex-Im Bank’s loan volume has decreased as the economy has recovered, not increased. In 2012, for example, the bank guaranteed $36.5 billion worth of loans. In 2014, it guaranteed $20.5 billion worth of financing, a decrease of 43 percent, he says, partly because private banks are more liquid and lending again to small businesses.

Additionally, when it comes to large companies such as Caterpillar and Boeing, the bank isn’t just supporting one company with its many thousands of workers, but--as in Boeing's case--the 6,600 small businesses that also supply the company with component parts, products, and services.

It’s also allowing customers overseas to make bets on long-term purchases. Recently, Ex-Im Bank guaranteed financing for Copa Airlines, of Panama, so it could purchase 61 new aircraft from Boeing, worth an estimated $6 billion, Hochberg says. The financing is vital to both sides of the deal, because it will take up to nine years to complete the delivery.

“Our footprint goes beyond what we finance, because Copa said it might not buy 61 planes without knowing it could finance them when they needed to,” Hochberg says.

That’s not to say the Ex-Im Bank hasn’t seen its share of problems. Last summer, four Ex-Im officials were removed or suspended for suspected kickbacks, gifts, and other alleged malfeasance. Also last year, the Congressional Budget Office issued a report suggesting the bank may cost taxpayers money after all, using the fair-value accounting method, which accounts for market risks of the loans the agency makes.

Exporting for Growth

Meanwhile, the debate over the bank unfolded as Congress also considered nixing two trade bills that would give U.S. businesses a leading role in Asia, and more parity in Europe. One of the trade bills, the Trans-Pacific Partnership, could also give businesses access to more than 40 percent of consumer markets globally, by some estimates. (Congress ultimately voted in late June to give the president authority to proceed with the bills.)

Yet the anti-export sentiment is especially problematic, some economic experts argue, because exports have played a leading role in the economic recovery.

U.S. exports supported nearly 12 million jobs in 2014, according to an April report from the International Trade Administration, a division of the Department of Commerce, an increase of 1 million jobs since 2009. And nearly one third of all economic growth since 2009 has been driven by exports, according to Commerce Secretary Penny Pritzker.

What’s more, the business environment has changed today, Hochberg says, driven primarily by the Internet and the potential for global commerce.

“Twenty years ago, the thinking was, when I have exhausted the U.S. market, I will look overseas,” Hochberg says. “Today, people are thinking about exporting when they start their businesses.”