Former Congresswoman Cynthia McKinney was nominated presidential candidate on Sunday by the liberal environmentalist Green Party.

After winning the nomination despite some fierce competition during its convention in Chicago, Illinois, the 53-year-old former Congresswoman picked journalist and activist Rosa Clemente as her running mate.

McKinney, who had to leave her office two years ago due to a controversial scuffle with a Capitol Hill police officer, received 313 votes of a possible 532 at the Green Party’s national convention. Ralph Nader, who’s already running as an independent candidate, was second with 78.5 votes. He was the most successful Green Party candidate so far as he managed to gather nearly 3 percent of the vote in 2000.

In her speech, McKinney condemned the war in Iraq and criticized both Democrats and Republicans for being influenced to corrupt corporate interests.

The former Democrat had announced her intention to run for the presidency as a Green Party candidate late last year. McKinney, who was the first black woman elected to Congress from Georgia, served six terms in Washington representing a suburban Atlanta district but was defeated in 2006 by DeKalb County Commissioner Hank Johnson.

As Green Party spokeswoman Scott McLarty recognized, McKinney is a "long shot" for the White House, but every vote she grabs will help the Green Party.

"The United States needs an alternative party," McLarty said. "The narrow two-party system we have right now has not served us very well."

McKinney was first elected in 1992, but she lost a primary challenge 10 years later after she said in a radio interview that members of the Bush administration profited from the war that followed the September 11, 2001, terrorist attacks on New York and Washington.