The most predominant denominations among residents in DeKalb County who adhere to a religion are Southern Baptists (37.63%), United Methodists (19.88%) and Community of Christ (14.82%).

Daviess County, along with the rest of the state of Missouri, is represented in the U.S. Senate by Josh Hawley (R-Columbia) and Roy Blunt (R-Strafford).

Like most rural areas throughout northwest Missouri, voters in DeKalb County generally adhere to socially and culturally conservative principles which tend to influence their Republican leanings, at least on the state and national levels.

On the Democratic side, former Vice President Joe Biden (D-Delaware) both won statewide and carried DeKalb County by a wide margin.

Incumbent President Donald Trump (R-Florida) faced a primary challenge from former Massachusetts Governor Bill Weld, but won both Daviess County and statewide by large margins.

Businessman Donald Trump (R-New York) narrowly won both DeKalb County and the state overall.

On the Democratic side, former Secretary of State Hillary Clinton (D-New York) won statewide by a small margin, but lost DeKalb County to Senator Bernie Sanders (I-Vermont).

Senator Rick Santorum (R-Pennsylvania), who finished first in the state at large, but eventually lost the nomination to former Governor Mitt Romney (R-Massachusetts).

In 2008, the Missouri Republican Presidential Primary was closely contested, with Senator John McCain (R-Arizona) prevailing and eventually winning the nomination.

Former Governor Mitt Romney (R-Massachusetts) won the vote in Caldwell County.

Then-Senator Hillary Clinton (D-New York) received more votes than any candidate from either party in DeKalb County during the 2008 presidential primary.

Despite initial reports that Clinton had won Missouri, Barack Obama (D-Illinois), also a Senator at the time, narrowly defeated her statewide and later became that year's Democratic nominee, going on to win the presidency.