South Dakota Democratic Party
|Chairperson||Randy Seiler |
|Headquarters||Sioux Falls, SD|
|Political position||Center to Center-left|
|National affiliation||Democratic Party|
|Seats in the Upper House|
5 / 35
|Seats in the Lower House|
11 / 70
Since its inception in 1889, South Dakota has been a Republican-leaning state through most of its existence, despite substantial changes to political party platforms. The history of the state's Democratic Party can be condensed into two separate time periods, each marked by a very different national atmosphere and legislative approach to past agrarian policy.
1914 was a milestone for the Democrats when they won South Dakota's first senate election by popular vote with their first statewide elected official, Edwin S. Johnson. This was their first success since William Jennings Bryan successfully campaigned (a novelty at the time) for the state's electoral votes in 1896 with help from an agrarian crisis. Nevertheless, it wasn't until the sweeping elections of 1932 that the Democratic Party took firm control as the party of the New Deal. With supermajorities in the state legislature and control of the governorship, the Democrats were able to set about securing newly available federal aid, replacing property tax with income and sales taxes, and instituting unemployment insurance. 
While Democrats managed only one solid two-year election cycle in the 40s and 50s, a young 2-term House member and Kennedy administration veteran with a strong understanding of agricultural policy, George McGovern, changed the party's fortunes when he squeaked out a win against incumbent Joe Foss in 1962's Senate election. An ardent opponent of the Vietnam War, McGovern's popularity and profile were on an upward trajectory that would only be shadowed by his presidential run in 1972. Despite his landslide loss to Republican incumbent Richard Nixon, he continued to serve in the U.S. Senate for 9 more years as his party came to power at the state level.
Forty years after the New Dealers had brokered a tenuous, short-lived agreement with the farmers and workers of South Dakota and ninety years after The Boy Orator of the Platte wooed voters on his "Whirlwind through the Midwest", the Democrats were back. This time, they rode two decades of failed farm politics and favorite son McGovern's election bid to a slim 1 seat majority in the Senate, even slimmer tie breaking control in the House and a re-election win by Governor Richard F. Kneip. An electronic voterbase and superior get-out-the-vote operation helped many overcome long-time Republican incumbents who'd become lethargic campaigners. 
At about the same time in 1968, South Dakota Democrats gained a relatively small but increasingly active voting group when the Indian Civil Rights Act was passed.  Since then, the state has created house districts 28A (in 1996) and 26A (in 2012) as majority-minority districts. These seats have been mostly reliably blue in an otherwise sea of red outside larger cities.
Since their heyday in the seventies, the South Dakota Democrats have since seen their influence decline in the state, in large part due to divisions within the state party caused by wedge issues like Roe v. Wade and the Oahe Irrigation Project.  Oahe was supported by party leaders like George McGovern but blocked by environmentalists as well as the Democratic President at the time, Jimmy Carter.  This splintering was only magnified by the fading of McGovern from the political spotlight, a liberal mainline Protestant who had tried to keep himself and his party insulated from the religiously conservative backlash against liberal social policies.  While most couldn't avoid the rightward drift of the state's politics (including McGovern himself), two Democratic representatives and senators, Tom Daschle and Tim Johnson, followed in his footsteps, each winning elections over the course of two decades in spite of an increasingly conservative statewide electorate that has generally voted for Republican presidents, governors and legislatures in recent election cycles.
Currently, 31% of South Dakota voters are registered as Democrats compared to 46% registered as Republicans,  putting the Democrats at a disadvantage in the state. Currently, Republicans hold every statewide elected office, as well as both of the state's seats in the United States Senate and its sole seat in the House of Representatives. In 2016, the Republicans had their best showing in the House in 40 years and won their record 12th straight presidential vote.  To those points, Democrats in South Dakota are now looking for a reset which will reshape the state party to draw in voters from all ideological backgrounds.
In September of 2019, the last two offices of the South Dakota Democratic Party closed down due to the lack of funding. 
The South Dakota Democratic Party does not hold any of the statewide offices and is a minority in both the South Dakota Senate and the South Dakota House of Representatives. Democrats have no members in the state's U.S Congressional delegation (the U.S Senate seats or the House At-Large seat).
- 5 seats in the State Senate and 11 seats in the State House 
- "Our People". South Dakota Democratic Party. Retrieved December 20, 2019.
- "Tom Berry". National Governors Association. Retrieved 18 October 2012.
- "Dakota Midday: The Democratic Surge Of The 1970s". SDPB Radio (Podcast). Friends of South Dakota Public Broadcasting. 7 July 2016. Retrieved 4 March 2017.
- Robert J. McCarthy, Civil Rights in Tribal Courts; The Indian Bill of Rights at 30 Years, 34 IDAHO LAW REVIEW 465 (1998).
- "The Collapse of the Democratic Party in South Dakota: What Happened?". Apple Valley, MN: PowerLine. 21 December 2014. Retrieved 4 March 2017.
- "A history of how a grassroots rebellion won a water war". High Country News. 12 April 1999. Retrieved 4 March 2017.
- "Voter Registration Tracking". Pierre, SD: South Dakota Secretary of State. Retrieved 4 March 2017.
- "5 most depressing statistics for South Dakota Democrats". Rapid City, SD: Rapid City Journal. 3 January 2016. Retrieved 4 March 2017.
- Pitofsky, Marina (2019-09-03). "Democratic Party closing last two offices in South Dakota". TheHill. Retrieved 2019-09-06.