Consumer advocate Ralph Nader on Monday will announce his candidacy for president under the banner of the Green Party, which has a progressive, anti-corporate agenda in addition to an emphasis on environmental issues. Nader ran as the Green nominee in 1996 and got 684,902 votes, including 2 percent of the vote in California. Some lefties felt that Nader ran a disappointingly half-hearted campaign the last time around, but he is expected to mount a more aggressive challenge this year. The goal is to get at least 5 percent of the vote nationwide, which would make the Green Party eligible to receive a proportional share of public funding for the next presidential campaign.