One of the sub-plots to the 2004 U-S presidential election is whether independent candidate Ralph Nader can win enough votes to affect the outcome.

Many Democrats say Mr. Nader cost their party the 2000 election by draining support from their candidate, former Vice President Al Gore.

Critics have urged Mr. Nader not to mount another campaign, and have even set up an Internet site called "Ralph Don't Run."

But the 70-year-old Mr. Nader has a long history of blazing his own trail, mainly as a consumer activist.

In the 1960s, he challenged big corporations, exposing poor safety standards in the food and automobile industries. Congress responded with tough new safety laws.

A few years later, his reports focused public attention on the problem of water and air pollution.  Congress responded again, creating the Environmental Protection Agency.

But much of the goodwill Mr. Nader earned from Democrats during those years has dissipated because of his campaigns for the presidency.

Mr. Nader insists that Mr. Gore was responsible for his own loss in the 2000 election.  As for 2004, Mr. Nader says he is running in order to "take government back from corporate interests that dominate both major U-S parties."

Opinion polls indicate he would win between four and six percent of the voters' support.   If the race between President Bush and his main challenger, Senator John Kerry, remains close, Mr. Nader could once again be a factor in who wins the White House.