Missouri GOP US Senate Barnburner Poised for Closest Primary Finish in 56 Years

Only three of the 35 Republican primaries for the U.S. Senate have been decided by less than 10 points in state history with the average margin of victory at more than 50 points

With eight candidates on the ballot, the Missouri GOP U.S. Senate contest appears to still be a three-candidate race heading into the last day of campaigning before Tuesday’s primary.

Businessman John Brunner has surged from a long-shot candidacy last fall to a potential favorite in one of many high profile Republican senate primaries held in the 2012 cycle.

Brunner is matched up against six-term U.S. Representative Todd Akin, former Missouri Treasurer Sarah Steelman and five other lesser-known candidates in what will go down as one of the most competitive Republican U.S. Senate primaries in state history.

A Smart Politics analysis finds that Missouri’s 2012 Republican U.S. Senate primary is slated to be just the fourth out of 36 such contests in state history to be decided by single-digits, with a historical average victory margin of more than 50 points.

Only two Missouri Republicans have ever received a free pass to the general election over the past century.

One-term incumbent Roscoe Peterson ran uncontested in 1934 as did two-term incumbent John Danforth in 1988.

Despite this history, Missouri GOP U.S. Senate primaries have largely been snoozers cycle after cycle, with the average victory margin coming in at 52.3 points.

Republican incumbents have won all 11 primaries in which they have run for reelection by an average of 68.5 points while the 24 primaries without GOP U.S. Senators in the race were decided by an average of 44.9 points.

The margin of victory in Tuesday’s contest, however, is likely to be in the single digits, and low single digits at that.

Only three of the 35 U.S. Senate primaries in party history have been decided by single digits with the most narrowly decided contest occurring during the 1956 cycle.

In that race, Herbert Douglas (40.8 percent) defeated Albert Schoenbeck (38.5 percent) by just 2.3 points with William Thomas a distant third out of four candidates with 14.1 percent of the vote.

Douglas subsequently lost to one-term Democratic incumbent Thomas Hennings by 12.8 points that November.

But the most competitive race to date was the primary of 1928 when U.S. District Attorney and former 1-term U.S. Representative Roscoe Patterson won the primary with just 31.4 percent of the vote – some 3.4 points ahead of former 1-term U.S. House member Nathan Frank (28.0 percent) with a third candidate – David Proctor – just 5.0 points back at 26.4 percent in a six-candidate field.

Patterson would win the general election that fall but then lost by nearly 20 points in his reelection bid to Harry Truman in the 1934 cycle.

Only one other Republican primary in the state has been decided by less than 10 points (R.R. Brewster’s 8.1-point victory in 1922) and only three others have been decided by less than 20 points (in 1920, 1940, and 1958).

The most competitive U.S. Senate primary for the Republican Party since the 1960s was a 35.8-point blow-out by St. Louis County Chief Executive Gene McNary over State Senator David Doctorian in 1980.

The 1928 race mentioned above most closely resembles what is likely to happen on Tuesday.

Brunner, Akin, and Steelman will all easily land in double-digits, with each candidate probably winning north of 20 percent of the vote.

The last time a trio of Republican U.S. Senate primary candidates received even 10 percent of the vote in the Show-Me state was over 50 years ago in 1958 when Hazel Palmer (44.6 percent), perennial candidate William Thomas (26.5 percent), and Homer Cotton (19.6 percent) accomplished that feat.

Palmer went on to get trounced by Democratic incumbent Stuart Symington in the general election.

From the first senate primary in 1914 through 1958 there were nine cycles in which three Missouri Republican candidates received at least 10 percent of the vote (1916, 1920, 1926, 1928, 1940, 1944, 1946, 1956, 1958), one in which four candidates reached double-digits (1932), and another in which five candidates reached that milestone (1922).

Margin of Victory in Missouri Republican U.S. Senate Primaries, 1914-2010

Year	Winner	%	2nd Place	%	MoV
2010	Roy Blunt	71.0	Chuck Purgason	13.1	57.9
2006	Jim Talent	88.9	Scott Babbitt	4.1	84.8
2004	Kit Bond	88.1	Mike Steger	11.9	76.2
2002	Jim Talent	89.6	Joseph May	4.2	85.4
1998	Kit Bond	86.9	Joyce Lea	3.9	83.0
1994	John Ashcroft	83.2	Joyce Lea	4.9	78.3
1992	Kit Bond	82.7	Wes Hummel	17.3	65.4
1988	John Danforth	100.0	(unopposed)	0.0	100.0
1986	Kit Bond	88.9	Richard Gimpelson	3.9	85.0
1982	John Danforth	73.9	Mel Hancock	20.9	53.0
1980	Gene McNary	61.5	David Doctorian	25.7	35.8
1976	John Danforth	93.5	Gregory Hansman	6.5	87.0
1974	Thomas Curtis	81.9	Paul Robinett	10.1	71.8
1970	John Danforth	72.6	Doris Landfather	19.7	52.9
1968	Thomas Curtis	84.5	Morris Duncan	10.8	73.7
1964	Jean Bradshaw	78.2	Morris Duncan	21.8	56.4
1962	Crosby Kemper	66.6	Duane Cox	13.2	53.4
1958	Hazel Palmer	44.6	William Thomas	26.5	18.1
1956	Herbert Douglas	40.8	Albert Schoenbeck	38.5	2.3
1952	James Kem	84.3	William Thomas	11.0	73.3
1950	Forrest Donnell	84.9	William Thomas	7.4	77.5
1946	James Kem	54.6	William Thomas	14.7	39.9
1944	Forrest Donnell	49.6	Howard Stephens	21.6	28.0
1940	Manvel Davis	40.8	David Proctor	28.6	12.2
1938	Henry Caulfield	86.0	Ray White	14.0	72.0
1934	Roscoe Patterson	100.0	(unopposed)	0.0	100.0
1932	Henry Kiel	50.4	Dewey Short	21.0	29.4
1928	Roscoe Patterson	31.4	Nathan Frank	28.0	3.4
1926	George Williams	56.5	David Proctor	28.2	28.3
1926 (s)	George Williams	75.7	Blogdett Priest	24.3	51.4
1922	R.R. Brewster	33.4	William Sacks	25.3	8.1
1920	Seldon Spencer	49.7	Dwight Davis	38.2	11.5
1918 (s)	Seldon Spencer	63.7	Jay Torrey	36.3	27.4
1916	Walter Dickey	51.3	Thomas Akins	29.8	21.5
1914	Thomas Akins	63.6	Politte Elvins	36.5	27.1
Average		70.1		17.8	52.3

Table compiled by Smart Politics.

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