A little-noticed bill pending before the Senate Judiciary Committee would give federal officials significantly more money, resources and power to crack down on public corruption.

Authored by Judiciary Chairman Patrick Leahy, D-Vt., and Sen. John Cornyn, R-Texas, the Public Corruption Prosecution Improvements Act would boost funding for federal public corruption investigations by $100 million over four years. It would also make it easier for Justice Department and other investigators to prosecute federal gratuities violations. A Judiciary Committee markup is scheduled for Thursday.

Lawmakers rarely jump at the chance to impose stricter rules on themselves -- indeed, a virtually identical version of the bill was downed by the GOP in the previous Congress. But the fact that recent corruption probes have netted Democrats and Republicans alike may create an opening. There's a "unique opportunity" to enact the bill this year, a Leahy aide said, since "nobody is going to see it as a partisan attack against them."

Even in clear corruption cases, it can be impossible to establish a clear link between a specific payment and a specific official act, the bill's backers say.

Recent court cases have substantially narrowed federal bribery and gratuities statutes, say legal experts, making it almost impossible to prove that a public official accepted gifts or payments illegally. The bill would more broadly define how existing laws apply to corruption offences and "eliminate legal ambiguities" that make them tough to prosecute, Leahy said on introducing the bill with Cornyn on the first day of this Congress.

"This is just restoring the bribery and gratuities statutes to their former intent," said Tara Malloy, associate legal counsel for the Campaign Legal Center, one of several good-government groups backing the bill.

The two key cases that have hamstrung federal prosecutors lately are the Supreme Court's 1999 United States v. Sun-Diamond decision, and a more recent lower court ruling dubbed United States v. Valdes.

In the Sun-Diamond case, the high court rejected charges that then-Agriculture Secretary Mike Espy illegally accepted some $6,000 in gifts, meals and other gratuities from the Sun-Diamond Growers Association despite the growers' stake in pending Agriculture Department regulations. Espy could not be prosecuted simply because of his official position, the Supreme Court found; instead, the gratuities would have had to be linked to a specific official act.

Similarly, the U.S. Circuit Court of Appeals for the D.C. Circuit ruled in 2007 that police officer Nelson Valdes did not violate gratuities laws when he took $400 from an undercover FBI informant in exchange for handing over information from a restricted police database. The data retrieval was not an "official act," the circuit court ruled, and therefore did not violate gratuities laws.

But those rulings gut the law because even in clear corruption cases, it can be impossible to establish a clear link between a specific payment and a specific official act, the bill's backers say. The Leahy-Cornyn bill clarifies that the gratuities law bans any benefits given to a public official "for or because of" that official's position. It also defines "official act" more broadly to include "any action within the range of official duty."

The bill is needed notwithstanding several recent high-profile prosecutions of public officials, Leahy maintains. Public corruption enforcement has waned since the Sept. 11, 2001, terrorist attacks, Leahy says, as federal resources have shifted away from white-collar crime to anti-terrorism activities. He points to a study by the Transactional Records Access Clearinghouse that found a 27 percent drop in prosecutions of white-collar crimes since 2000, and a 14 percent drop in official corruption cases in the same period.

Moreover, many of those caught in recent scandals, including lobbyist Jack Abramoff, former Rep. Bob Ney, R-Ohio, and several former Capitol Hill aides and lobbyists, faced prosecution under charges of honest-services fraud, not bribery and gratuities statutes. That's in part because recent court rulings have made it so hard to prosecute bribery and gratuities offenses, reform advocates say.

The scandal involving Rep. William Jefferson, D-La., also points up the damage done by the recent Valdes ruling, in particular, Malloy said. Jefferson has turned to Valdes as a defense as he battles bribery and wire fraud allegations. His lawyers argue that the $100,000 Jefferson received in exchange for promoting donors' business interests in the U.S. and abroad, including $90,000 found in his freezer, was not illegal because his dealings were not "official" in nature.

The Leahy-Cornyn bill may face some opposition on the Judiciary panel from ranking member Arlen Specter, R-Pa. During last year's markup, Specter voiced concerns that the bill could give prosecutors too much power and make public officials vulnerable to politically motivated investigations. Leahy responded with amendments -- carried over to this session -- that make clear that token gifts, such as baseball caps, are exempted, and that legal campaign contributions would not count as gratuities.

Even if it's tailored further, the bill would be a step forward in cleaning up behind-the-scenes money. If enacted, it would significantly impact public officials both on Capitol Hill and in the state legislatures, said Fred Wertheimer of Democracy 21. He added: "This is an unnoticed but very important issue."

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