Next month, the United States will finally elect its next president after nearly two years of campaigning, fundraising, scandals, and debates.

The Democratic party has never been perfectly unified. In this year’s Democratic primary, disagreements among registered Democrats seemed especially acute. Approximately 12 million Americans voted for former presidential candidate Bernie Sanders, versus the 15.8 million who voted for nominee Hillary Clinton. Some portion of voters who supported Sanders in the primary will likely either not vote, or cast a ballot for a third-party candidate.

Yet, the country’s two-party political system is so structurally entrenched that the majority of states that went for Democratic candidate Barack Obama in 2012 appear likely to go for Clinton this time as well. While the political platform of a party and the candidates within that party can change over time, it seems that a portion of the population will always vote Republican or Democrat no matter who is running for president.

22. Michigan

>Bluest county: Genesee County

Genesee County has sent a Democrat to the U.S. House of Representatives in each of the last five congressional elections. Also, 63.6% of Genesee County voters chose Obama over Romney in 2012, one of the highest shares of any county in Michigan. Like many counties inclined to vote Democratic, Genesee County’s median household income of $41,879 is substantially lower than the national median of $52,482. Additionally, 21.2% of Genesee County residents live in poverty compared to 15.6% of Americans.

Based on voting data compiled by political news organization Politico and a review of current and historical representation in the U.S. Congress, 24/7 Wall St. created an index to measure the political leanings of county residents. The index is based on the political party of the county’s elected representatives to the Senate and House of Representatives through the last five election cycles, as well as the results of the 2012 presidential election. Prince George’s County in Maryland is not just the bluest county in the state, but also in the nation.

Even in the most conservative states, there is at least one county that has strong Democratic leanings. In Alabama, 61% of total voters opted for Republican candidate Mitt Romney in the 2012 elections, one of the highest shares the losing the candidate received of any state. Yet, in Greene County, nearly 85% of voters cast ballots for Obama. While the state has had Republican representation in the Senate for years, Greene County’s congresswoman, Terri Sewell of Alabama’s 7th district, is a Democrat. Sewell’s predecessor, Artur Davis, is also a Democrat.

While both those counties lean heavily Democratic and the reddest states each tend to have low incomes, adults in the blue counties tend to have higher educational attainment rates compared to the reddest counties. In 33 states, adults in the most Democratic county had a higher bachelor’s attainment rate than those in the most conservative-leaning state.

Race clearly bears a strong relationship to political affiliation in these counties. In only three of the reddest counties, a lower share of residents identify as white than the national share of 63% of Americans who identify as white. On the other hand, 28 of the bluest counties have smaller shares of white populations compared to the national average composition.

Click here to see the most Democratic county in every state.

Click here to see the most Republican county in every state.

Click here to read our methodology.