Such reports have given the White House and Republicans an opening to attack the likely independent challenger for the Presidency.

There were, however, a number of strong independent challengers, the most notable of whom was Mary Starrett, the Constitution Party nominee.

An independent third-party challenger, Tom Scott, who led and organized the 1991 protests, has gone one better, promising to do it in four years.

Incumbent mayor Luke Ravenstahl, a Democrat, defeated his two independent challengers by a wide margin.

Anderson ran as an independent challenger, and Clay's candidacy predated the rise of the modern two-party system.

Their all-but-declared independent challenger, Ross Perot, fared better, but the percentage of voters who view him negatively has more than doubled in six weeks.

She was re-elected unopposed in 2008 and faced only independent challengers in 2010 (including Ted Downing), prevailing easily.

At Dartmouth, alumni elect half of the college's 18 trustees, either Alumni Association nominees or independent challengers.

The main reason is that Mr. Powell's stock as an independent challenger continues to rise as loyalty to the political parties declines.

Meek was overwhelmingly elected to a third term with no Republican or independent challenger.