Complex sentence: He ran unsuccessfully for Mayor of Toledo, Ohio in 2009, after a heckler booed him and called him a liar for going back on his pledge to remain in his county commissioner seat until his full term was up.
Split into simpler sentences: He ran unsuccessfully for Mayor of Toledo, Ohio in 2009. During the campaign a heckler booed him and called him a liar for going back on his pledge to remain in his county commissioner seat until his full term was up.