Elliott County had voted for the Democratic Party's nominee in every presidential election since it was formed in 1869, up until the 2016 presidential election when it voted 70-26 in favor of Donald Trump. This was the longest streak of any county voting Democratic in the United States. It was also the last Southern rural county to have never voted for a Republican in any Presidential election, until 2016. Even in nationwide Republican landslides like 1972 and 1984, when Republicans were winning the state of Kentucky overall with more than 60% of the vote, Elliot County voted 65.3% and 73.4% Democratic, respectively.

As of the census of 2000, there were 6,748 people, 2,638 households, and 1,925 families residing in the county. The population density was 29 per square mile (11/km). There were 3,107 housing units at an average density of 13 per square mile (5.0/km). The racial makeup of the county was 99.04% White, 0.03% Black or African American, 0.07% Native American, 0.01% Pacific Islander, 0.01% from other races, and 0.83% from two or more races. 0.59% of the population were Hispanic or Latino of any race.

Elliott County was the second-whitest county in the country, at 99.04%, to vote for Democrat Barack Obama in the 2008 Presidential election, the whitest being Mitchell County, Iowa. Obama garnered 61% of the vote, while Republican John McCain received 36%. In 2008, Elliott County provided Obama with the highest winning percentage of the vote out of all Kentucky counties. This made it the most Democratic county in the state for the 2nd election in a row, since it had also been Democrat John Kerry's strongest county in Kentucky in 2004. Obama would again win the county in 2012, his only county victory in traditionally staunchly conservative rural Eastern Kentucky. However he would only eke out a narrow 49% plurality over Mitt Romney's 47%, a lead of just 60 votes, thus nearly ending a long streak of Democratic landslides in Elliott County. Reflecting the increased rural-urban divide in modern American politics, Obama's strongest county in the state was instead Jefferson County, home to the state's largest city, Louisville, which he won by a much more comfortable 54.69%-43.60% margin.

As of 2014, Elliott County had the fewest number of registered Republicans, 248, out of all counties in Kentucky. By 2016, it had increased to 429, out of 5,214 registered voters.

In 2016, Elliott County voted for Donald Trump, the Republican candidate, by 2,000 votes (70.1%) to 740 (25.9%) for Democrat Hillary Clinton, decisively ending the Democratic Party's 144 year victory streak. Despite this feat, Trump's victory carried no coattails in the county during the coinciding senate race as Jim Gray, the Democratic nominee, won the county by 1,477 votes (56.07%) to 1,157 (43.93%) for Republican Senator Rand Paul. However, the area the County occupies voted Republican in the 1868 election, a year before the County was founded.