A U.S. lawmaker and civil rights leader who previously supported Democratic presidential candidate Hillary Clinton has announced he will now support her rival, Senator Barack Obama.

Representative John Lewis

Representative John Lewis from Georgia said Wednesday that his congressional district overwhelmingly supports Obama. Lewis was a prominent black leader of the civil rights movement of the 1960's. Obama also is African-American and has received majority support from black voters.

Senator Clinton's campaign is hoping that wins in critical primaries in Ohio and Texas on March 4 will help her keep pace with Obama, who has 11 straight wins in nominating contests.

In other news, New York Mayor Michael Bloomberg has announced he will not be entering the presidential race, ending widespread speculation that he might run.

In an opinion piece in the New York Times, Bloomberg said he might be willing to lend support to a candidate who takes a non-partisan approach.

On Sunday, consumer advocate Ralph Nader announced his own plans to enter the race as an independent candidate.

In the Republican field, Senator John McCain, a veteran Arizona lawmaker, is holding on to a commanding lead over rival Mike Huckabee for their party's nomination.

Some information for this report was provided by AFP, AP.