The 4th was one of the first areas of Kentucky to turn Republican outside of traditionally Republican south-central Kentucky; it has been in GOP hands for all but six years since 1967. Its politics are dominated by Republicans in the wealthy Cincinnati suburbs, which have swelled with former Cincinnati residents since the early 1960s. Between them, Boone, Kenton and Campbell counties have as many people as the rest of the district combined. As a measure of how much the Cincinnati suburbs have dominated the district, when Massie took office, he became the first congressman from the district's eastern portion in 45 years. Nonetheless, Democrats still hold state and local offices in rural counties.
As of November 7, 2006, there were a total of 476,480 registered voters. Of these, 250,986 (52.67%) identified as Democrats, 184,705 (38.76%) identified as Republicans, and 40,789 (8.56%) identified as "Others."
Until January 1, 2006, Kentucky did not track party affiliation for registered voters who were neither Democratic nor Republican. The Kentucky voter registration card does not explicitly list anything other than Democratic Party, Republican Party, or Other, with the "Other" option having a blank line and no instructions on how to register as something else.
Living former Members of the U.S. House of RepresentativesEdit
As of June 2017[update], two former member of the U.S. House of Representatives from Kentucky's 4th congressional district are alive. The most recent representative to die was Jim Bunning (served 1987–1999) on May 26, 2017.