Coattail effect refers to the tendency of a popular political leader attracting votes for other candidates of the same party in an election. It can influence the outcome of an election. It may be a boost for candidates lower down the ballot when a successful candidate of their party runs strong at the top of the ballot. For example, a popular presidential candidate who won a large percentage of the vote might carry other party candidates into office. It may be said then that, their win is on his/her coattails.