Congress has a choice to make, with a deadline of June 30. It can either renew the authorization of the Export-Import Bank — a taxpayer-backed credit agency that picks winners and losers in the marketplace — or let it expire and begin the bank's orderly winding-down.

As conservatives, we believe that one of Congress' top responsibilities is to protect taxpayers from corruption, waste and mismanagement. That is why we support letting Ex-Im expire. Congressional oversight has revealed that the bank is broken, ignores opportunities for reform and proves a financial liability to American taxpayers.

Originally, Ex-Im was conceived to help small American businesses compete with the Soviet Union. It has evolved from a Cold War relic to become a prime example of the perils of Washington's "government knows best" philosophy.

The bureaucrats who run the bank believe that government can outwit markets and help some businesses at the expense of others. We know, however, that America can compete in a modern global economy without interference from bureaucrats. In fact, the best thing Washington can do to help our economy thrive is to enact common-sense tax reforms, unleash America's energy production and lower the barriers for international trade.

Unfortunately, Ex-Im is more than an outdated agency — it is fundamentally broken. And it should come as no surprise that when such an agency wields the heavy hand of governmental power, mismanagement, misconduct and corruption become the norm. It is a modern day "Enron" of the federal government.

Take, for instance, the case of former Ex-Im official Johnny Gutierrez, who pleaded guilty just last month to accepting nearly $79,000 in bribes. On 19 separate occasions between 2006-13, Gutierrez accepted cash in return for recommending the bank approve certain unqualified loan applications.

This example is not isolated. At a recent congressional hearing on Ex-Im, House Financial Services Chairman Jeb Hensarling, R-Texas, pointed out that Ex-Im has seen an overall increase in criminal charges since President Obama appointed Chairman Fred Hochberg to head it six years ago. According to the chairman, the supposedly small bank's rap sheet is impressive: "Sixty-five matters have been referred to prosecution, 31 arrest warrants, 85 indictments, 48 criminal judgments, decades of combined prison time, a quarter of billion in fines, restitution and forfeiture."

Those numbers may soon rise even higher — at the same hearing, Ex-Im's inspector general testified that there are at least 31 open fraud investigations involving Ex-Im that could lead to future indictments.

Ex-Im's employee misconduct is a symptom of a larger problem. The bank has simply proven itself incapable of reform. Congress, the General Accountability Office and the bank's own inspector general have made numerous recommendations to "fix" Ex-Im, which its officials have boldly ignored. After years of repeated warnings, the bank has made clear that they have no interest in changing their troubling and irresponsible practices — and they are putting taxpayers at risk in the process.

According to Ex-Im's IG, the bank does not subject borrowers to the same level of scrutiny that private lenders do, and it has no robust and systematic process for keeping an eye on borrowers. The standards for underwriting loans are also decentralized and potentially subjective, as well. In 2010, the Bank's board of directors authorized certain officials to approve loan applications under $10 million, raising concern that the bank was no longer doing its due diligence or applying a uniform standard for loan approval. The IG recommended Ex-Im improve its credit underwriting process, but there is no indication these changes have been implemented.

Ex-Im has also ignored recommendations to manage its risk, as wise private investors do, by diversifying its portfolio geographically and by sector. As a result, its portfolio is too heavily concentrated in a handful of industries. If a sector of the economy heavily subsidized by Ex-Im — like aerospace, for example — were to suffer, taxpayers could be on the hook for billions of dollars in bad loans.

We have paid for such bad decisions before. The painful lessons of Fannie Mae and Freddie Mac should not go unheeded. Congress made it clear that Ex-Im needs to reform the way it does business, but Ex-Im has made it clear it will not change. Ex-Im is at risk of becoming another Enron — that legendary corporate example of mismanagement and misconduct, which itself once benefited from Ex-Im financing.

The government should not be in the banking business to begin with, but a government bank that defies the government's elected representatives is even more inappropriate. We are both determined to let Ex-Im begin what will likely be a 20-year process of winding down its operations in order to protect taxpayers and pave the way for a freer, more prosperous economic future.

Op-ed originally published in the Washington Examiner