In just over a month, the United States will finally elect its next president after close to two years of campaigning, fundraising, scandals, and debates.

Republican candidate Donald Trump is considered an outsider to politics and the party. As a result — and because Trump’s views have sometimes clashed with the party’s vision — some have wondered whether this election might be less divided along party lines than in recent elections. Despite the division within the Republican Party, most major polls suggest that the majority of states will vote the same as in the past several elections. It seems that a portion of the population will always vote Republican or Democrat no matter who is running for president.

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 U.S. counties’ 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.

22. Michigan

> Reddest county: Ottawa County

Michigan has gone to a Democrat in every presidential election since 1992, including supporting President Obama in 2012 with 54% of the votes. In Ottawa County, however, 66.7% of the votes were for Republican candidate Romney, the highest share of any county in Michigan. Unlike predominantly Republican counties in most states, more than 30% of residents have at least a bachelor’s degree, a slightly higher educational attainment rate than the national rate.

Even in the most liberal states there is at least one county that has strong Republican leanings. In Illinois, 57% of the electorate voted for President Barack Obama, the state’s former senator. Yet, in Wayne County, less than 20% of those who went to the polls voted for Obama. Wayne, which is in the state’s 15th congressional district, has been represented by a Republican for decades.

The racial composition of these counties can likely help explain the Republican leanings of the area’s residents. The vast majority of residents in most of the reddest counties identify as white. In 40 states, at least 80% of the population of the most Republican county identify as white. That was the case in just 12 of the bluest counties in each state.

Voters in the reddest counties were almost always more likely than residents of other counties to vote Republican during the 2012 presidential election, and the share of votes cast for then Republican candidate Mitt Romney was almost always greater than 50%. However, in four of the reddest counties — Honolulu County, Hawaii; Plymouth County, Massachusetts; Washington County, Rhode Island; and Essex County, Vermont — a majority of residents voted to reelect Obama in 2012. In these counties, Romney still captured the largest share of votes compared to other counties in the state.

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

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

Click here to read our methodology.