Sen. John Cornyn, R-Texas, is a rising star among conservatives in Congress, so it's especially significant that he has just won passage of the most significant open government reform in years.

The Senate approved June 24 by unanimous consent a Cornyn-backed measure that requires all bills being considered by Congress to make explicit any proposed exemptions to the Freedom of Information Act.

The FOIA guarantees every American the right to see any tax-paid government document on request, subject only to such reasonable exceptions as national security, law enforcement, commercial trade secrets and personal privacy.

Seeing a conservative leading an FOIA-related charge has been a rarity in recent years on Capitol Hill, but Cornyn's work with a hardy band of legislators, activists and journalists suggests a growing realization on the Right that big government's worst enemy is transparency.

Cornyn's bill was made necessary by a raft of bills in recent years that used obscure provisions tucked away in often-unrelated legislation to exempt some agencies and programs from the FOIA.

Among the more than 140 examples of obscure exemptions approved in recent years is one that prevents citizens from using the new national livestock identification system to learn about animals infected by mad cow disease (an exemption sponsored by Rep. Collin Peterson, D-Minn.).

According on Cornyn, the justification for his provision is simple. "Congress should not establish new secrecy provisions through secret means," he told the Senate. "If Congress is to establish a new exemption to FOIA, it should do so in the open and in the light of day."

Congress has used the Cornyn approach before, including the War Powers Resolution and the Federal Vacancies Reform Act, which also require Congress to act in an explicit fashion in order to carry out particular objectives, Cornyn added.

Senate passage doesn't mean the measure is law yet, as it must now be approved by the House of Representatives and signed by President Bush. Prospects in the House are unclear, but the White House said it was not opposed to the measure when it was first introduced.

The measure the Senate approved last week is part of a much bigger package of reforms Cornyn introduced in February called "The Open Government Act of 2005."

That measure is co-sponsored by Sen. Patrick Leahy, D-Vt., and a companion measure is being co-sponsored in the House by Rep. Lamar Smith, R-Texas, and Rep. Brad Sherman, D-Calif.

Among other things, the proposal provides concrete penalties for federal workers and agencies that violate the FOIA, and, in an effort to minimize legal costs, establishes an independent office to arbitrate disputes between FOIA requestors and denying agencies.

Despite favorable media on the proposal following a March hearing in the Senate and a May hearing in the House, many of its advocates expect the Cornyn-Leahy measure will require much time and debate before it becomes law.

The current FOIA became law July 4, 1966, after an epic 17-year struggle on its behalf. Among its original co-sponsors was Secretary of Defense Donald Rumsfeld, then a freshman GOP congressman.

Washington isn't the only place where conservatives are taking leading roles in making government more transparent. The Arlington, Va.-based Atlas Economic Research Foundation recently presented its prestigious Templeton Freedom Awards to FOIA activists in Bulgaria and the Philippines.

Atlas helps fund conservative organizations and projects in 67 nations and its Templeton Award - established in 2003 and named for Britain's Sir John Templeton - recognizes innovative work by think tanks and other non-governmental groups around the world.

In Bulgaria, Atlas recognized the Access to Information Program Foundation and in the Philippines, the Center for Media Freedom and Responsibility was recognized.

Despite passage in 2000 of its first-ever FOIA law, Bulgarian bureaucrats have been slow shaking off practices that typified the eastern European nation's years as one of the most repressive satellites of the Soviet Union. AIP is assisting more than 80 of the most egregious cases of "information refusal."

Upholding FOIA is a core principle of the Center for Media Freedom and Responsibility and its work in that area and in journalism ethics resulted in its receiving the Templeton.

As encouraging as the Atlas awards are internationally, it remains true that Cornyn's prospects for advancing FOIA reforms here depend greatly on more conservative leaders recognizing the power of transparency against Big Government.

Mark Tapscott is director of the Center for Media and Public Policy at The Heritage Foundation (heritage.org).