party ▁oppon ents ▁gain ▁control ▁of ▁one ▁or ▁both ▁houses ▁of ▁Congress . ▁ ▁Historical ▁record ▁of ▁mid term ▁ ▁Mid term ▁elections ▁are ▁sometimes ▁regarded ▁as ▁a ▁refer endum ▁on ▁the ▁sitting ▁president ' s ▁and / or ▁inc umb ent ▁party ' s ▁performance . ▁▁ ▁The ▁party ▁of ▁the ▁inc umb ent ▁president ▁tends ▁to ▁lose ▁ground ▁during ▁mid term ▁elections : ▁since ▁W W II ▁the ▁President ' s ▁party ▁has ▁lost ▁an ▁average ▁of ▁ 2 6 ▁seats ▁in ▁the ▁House , ▁and ▁an ▁average ▁of ▁four ▁seats ▁in ▁the ▁Senate . ▁ ▁Moreover , ▁since ▁direct ▁public ▁mid term ▁elections ▁were ▁introduced , ▁in ▁only ▁seven ▁of ▁those ▁( under ▁pres idents ▁Wood row ▁Wilson , ▁Franklin ▁D . ▁Ro ose vel t , ▁John ▁F . ▁Kennedy , ▁Richard ▁N ixon , ▁Bill ▁Cl inton , ▁ ▁George ▁W . ▁Bush ▁and ▁Donald ▁Trump ) ▁has ▁the ▁President ' s ▁party ▁gained ▁seats ▁in ▁the ▁House ▁or ▁the ▁Senate , ▁and ▁of ▁those ▁only ▁two ▁( 1 9 3 4 , ▁Franklin ▁D . ▁Ro ose vel t ▁and ▁ 2 0 0 2 , ▁George ▁ ▁W . ▁Bush ) ▁have ▁seen ▁the ▁President ' s ▁party ▁gain ▁seats ▁in ▁both ▁houses . ▁▁▁ 1 Part y ▁sh ading ▁shows ▁which ▁party ▁controls ▁chamber ▁after ▁that ▁election . ▁ ▁Com parison ▁with ▁other ▁U . S . ▁general ▁elections ▁ ▁Notes ▁ ▁References ▁ ▁External ▁links ▁▁▁ ▁Category : E lections ▁in ▁the ▁United ▁States