coattail effect

The term refers to the power of a popular candidate to gather support for other candidates running on the same party ticket. Winning candidates are said to have coattails when they drag candidates for lower office along with them to victory.

The expression dates from the mid-19th century when coats with tails were the fashion for men.

President Ronald Reagan was said to have coattails when his victory int he 1980 election was accompanied by the change of twelve seats in the U.S. Senate from Democratic to Republican hands, producing a Republican majority in the Senate for the first time since 1954.