Sen. Chris Murphy is right to want to protect American businesses and jobs from being undercut by cheaper foreign goods.

That — and reaping political benefit, no doubt — is why he's long hewed to a "Buy American" agenda. Though he's been criticized, a little protectionism isn't so bad if it keeps workers at home employed.

Mr. Murphy fought for "Buy American" legislation as a Democratic member of the House. Last year, in his first full year in the Senate, he introduced the "American Jobs Matter Act," requiring the Department of Defense to take U.S. job growth into account when choosing a contractor. The act is meant to help U.S. military manufacturers and suppliers compete with foreign companies.

"We should have a simple rule in this country that when we purchase things for the U.S. government — particularly the U.S. military — we should give preference to U.S. companies. That has not been the case," he said then.

Last week, he fired potshots at violators of the "Buy American Act," which requires federal agencies to buy at least 50 percent of the goods they need from American manufacturers. The law allows agencies to file a waiver if they can't find what they need in this country.

He noted that in the past seven years, the Pentagon has spent more than $160 billion of taxpayer money on foreign-made goods.

Mr. Murphy believes waivers are often abused, that contractors buy goods abroad if they're cheaper, even if they are available in the United States. He is on target in wanting the law more strictly enforced.

His approach is not risk-free. Such measures can have unintended consequences — higher prices for taxpayers, for example, or harm for important trading partners such as Canada.

In the long run, however, U.S. workers and the nation's security are best served with a "Buy American" bias when the federal government goes shopping.