The 1978 Maryland Senate election was held on November 7, 1978, to determine which party would control the Maryland Senate for the following four years. All 47 seats were up for election and the primary was held on September 12, 1978. Prior to the election, 39 seats were held by Democrats and 8 seats were held by Republicans. The general election saw the Democrats expand their majority by a single seat.
Retirements Democrats District 7: Donald P. Hutchinson retired to run for Baltimore County Executive. District 8: Roy N. Staten retired. District 13: John C. Coolahan retired. District 17: Charles W. Gilchrist retired to run for Montgomery County Executive. District 22: Meyer M. Emanuel Jr. retired. District 26: Steny Hoyer retired to run for lieutenant governor of Maryland alongside Blair Lee III. District 32: Alfred J. Lipin retired. District 34: Elroy G. Boyer retired.
Republicans District 5: C. A. Porter Hopkins retired. District 16: Newton I. Steers Jr. retired.
Incumbents defeated In primary Democrats District 19: C. Lawrence Wiser lost renomination to Sidney Kramer. District 36: E. Homer White Jr. lost renomination to Joseph J. Long Sr.
Closest races Seats where the margin of victory was under 10%:
(gain)
Results District 1
District 2
District 3
District 4
District 5
District 6
District 7
District 8
District 9
District 10
District 11
District 12
District 13
District 14
District 15
District 16
District 17
District 18
District 19
District 20
District 21
District 22
District 23
District 24
District 25
District 26
District 27
District 28
District 29
District 30
District 31
District 32
District 33
District 34
District 35
District 36
District 37
District 38
District 39
District 40
District 41
District 42
District 43
District 44
District 45
District 46
District 47
References