WASHINGTON — The Senate, warned that its public esteem had fallen to “the level of used-car dealers,” voted Wednesday to hobble the money chase for campaign funds and to ban outside speaking fees.

Democrats overrode longstanding Republican objections to limiting how much candidates can spend to win office by a 59-40 vote, largely along party lines, the first wholesale revamping of election laws since the Watergate era 16 years ago.

“The public is rapidly losing confidence in the federal election process,” said Senate Majority Leader George J. Mitchell. “It is clear we have gotten to the point that the worst alternative is to do nothing.”

Immediate skepticism was raised as to whether the campaign reforms or the accompanying elimination of honoraria that now allows senators to keep thousands of dollars in speaking fees each year will clear several remaining hurdles, including the renewed promise of a veto by President Bush.

“This bill clearly will not become law,” said Sen. Mitch McConnell, R-Ky. McConnell said he was told by White House Chief of Staff John Sununu earlier Wednedsday that Bush would veto it. “It will be vetoed, there’s no doubt about it,” added Sen. Don Nickles, R-Okla.

By a 77-23 vote earlier Wednesday, the Senate had voted to include in the bill Sen. Christopher Dodd’s amendment to ban pocketing of honoraria after Jan. 1, 1990, and limit any other outside earned income to 15 percent of Senate salaries. The House voted a similar ban for its members last year.

“When a significant part of our salaries comes from hustling, and that’s what it amounts to, we denigrate ourselves,” said Dodd, D-Conn. “As public servants, our salaries should come from the public alone.”

In addition to the spending caps, the reforms in the bill would abolish union, corporate and trade association political action committees that accounted for one-fourth of the $185 million spent on Senate elections in 1988.

House leaders said they hoped to vote Friday, before lawmakers begin a five-week vacation, on campaign finance reforms. But they acknowledged that it might not happen because of widespread discord among Democrats over the issue.

Unlike their party colleagues in the Senate, House Democrasts rejected calls to ban PACs, which have overwhelmingly favored them over Republicans in recent elections. Many also have voiced opposition that the proposed $550,000 spending cap for House races is too low to cover both primary and general election challenges.