There's but one fact worthy of consideration when mulling the dimension of the challenge facing Rep. Michele Bachmann (R-MN) in her White House bid:
The U.S. has elected only one House member directly to the presidency.
That was James Garfield in 1880. A longtime Congressman, Garfield had the advantage of having simultaneously been re-elected to his House seat and appointed to the U.S. Senate by the Ohio legislature at the time of his rise to the White House.