|(in the US) a politician popular in his home state but little admired beyond it|
A political figure nominated for the presidency by his or her state's delegation to the national nominating convention of a major party. Favorite sons are rarely serious candidates for the party's nomination. By nominating a favorite son, the delegation honors its nominee while delaying its commitment until the more serious contenders for the nomination can be sorted out.
A person valued by his or her hometown or organization for his or her achievements, usually political, as in Mary hoped they would treat her as a favorite son and nominate her for state senator. This term was originally employed for a candidate nominated for office by his own locality. Today this usage may ignore gender, as in the example. [c. 1780]