Since when has the incumbent challenged by R.J. Harris in 2010 served in Congress?
R. J. Harris:  In 2010, he unsuccessfully challenged incumbent Tom Cole for the Republican Party nomination in the primary election for Oklahoma's 4th congressional district. Tom Cole: Thomas Jeffery Cole (born April 28, 1949) is the U.S. Representative for Oklahoma 's 4 congressional district , serving since 2003.
i don't know