In 2008, the Republican Party declined to nominate a candidate in the 2008 Senate election in Arkansas. Thus, Kennedy became the sole challenger of Democratic Senator Mark Pryor in his first race as an incumbent. Kennedy received a 206,504 votes for 20.54% of the vote . This is the highest percentage of the vote for any Green Party candidate running for U.S. Senate ever, and her 206,504 votes is the second most total votes received by a Green Party candidate for U.S. Senate. Kennedy's campaign, in addition to being record breaking for the Green Party, was also the strongest showing of any independent or third party candidate running for the U.S. Senate in 2008.