Following the footsteps of other presidential contenders, Senator Barack Obama visited Los Angeles on Tuesday to raise funds for the campaign.

This is the first time he is in Los Angeles since he announced his presidential candidacy.

The Illinois Democrat will address a rally in the Crenshaw District later Tuesday, then attend a fund-raiser in Beverly Hills near downtown Los Angeles.

Obama declared at a fund-raiser in San Francisco on Monday that "we are in the midst of war that should have never been authorized or waged."

His aide said Obama is expected to explain in his Los Angeles speech that he is running for president because "he believes that to change our country, we need to change our politics".

Obama has called for withdrawing all combat units from Iraq by March 31, 2008.

In announcing his candidacy on Feb. 10, Obama said that " letting the Iraqis know that we will not be there forever is our last, best hope to pressure the Sunni and Shiite to come to the table and find peace."

Several presidential contenders are visiting Southern California these days, seeking to maximize their fund-raising in advance of the March 31 quarterly report deadline, a first test of the viability of their candidacies.

Sen Hillary Rodham Clinton, who is considered the front-runner for the Democratic nomination, is scheduled to meet with Los Angeles-area supporters Thursday, a day after a scheduled visit by Sen. Joseph Biden.

Visiting the Southland last week were former North Carolina Sen. John Edwards and former Iowa Gov. Tom Vilsack, both Democrats, and Republican former New York City Mayor Rudy Giuliani.

The 2008 presidential campaign will be "the longest and most expensive election in American history," Federal Election Commissioner Michael Toner said recently.

"We're heading into the first $1 billion election," he said.

To be competitive, a candidate will need 100 million dollars by the end of the year, he said.

The 2008 campaign is the first since 1928 in which neither a sitting president nor vice president is seeking the presidency.

In a USA Today/Gallup Poll of 495 Democrats and those leaning to the Democratic Party earlier this month, Obama was second with 21 percent, trailing Clinton, who had 40 percent. The margin of error was 5 percentage points.

Source: Xinhua