In his continuing push to set limits on campaign financing, Senator John McCain (R-AZ) has proposed new restrictions that include capping donations at $25,000 for independent political groups known as 527s, the New York Times reports.

The legislation is one of a series of measures proponents say will help protect the integrity of the 2002 McCain-Feingold campaign finance law. Although its prospects are uncertain, the bill has drawn early backing from the likes of President Bush and Sen. Trent Lott (R-MS), who is co-sponsoring the legislation and will hold hearings on it in the Senate Rules Committee, which he chairs. Democratic backers of the proposal include Sen. Russell D. Feingold (D-WI) and Sen. Charles E. Schumer (D-NY), who is in charge of fundraising for Senate Democrats.

The bill would require 527s to register with the Federal Election Commission and abide by its limits on fundraising and spending. Groups working only on federal elections would be treated like political action committees, which can accept individual donations up to a maximum of $5,000. In addition, any advertising a 527 bought to support a federal candidate would have to be paid for using this so-called hard money. Groups working on state and local campaigns in addition to federal campaigns would have to cover at least 50 percent of the cost of their advertising and voter-turnout efforts with hard money, and would have to abide by the $25,000 annual limit on soft money. Contributions from corporations and unions would be prohibited. The bill would not affect groups working exclusively on non-federal elections, that raised less than $25,000 a year, or that operated under Section 501(c) of the tax code.

McCain himself works with a nonprofit group called the Reform Institute in Alexandria, Virginia, that works to promote the reform of campaign finance laws and has, on occasion, accepted more than $50,000 from individual donors, some with ties to telecommunications companies. But the organization did not violate campaign finance laws, McCain told the Times, because it did not try to sway elections. "The overwhelming majority of 501(c)(3)s are advocacy organizations for different causes, and that's fine," said McCain. "That's what our system should be all about."