WASHINGTON - As the results come in from Iowa Monday night, keep an eye on a map of the returns. Where candidates are winning and losing could be just as important as the final tally.

Iowa is home to different kinds of communities and voters and Monday’s results could offer a glimpse of what various parts of the Democratic primary electorate think about the 2020 field. Consider this your caucus night cheat sheet for the places to watch.

Let’s start with Johnson and Story counties, home of the state’s big universities, Iowa and Iowa State.

As you might expect the colleges play an oversized role in both of these communities. More than 50 percent of the 25-and-over population in each has at least a bachelor’s degree and more than 20 percent of the population in each is enrolled in college in some way — undergrad or graduate.

If Sen. Bernie Sanders is having a good night, these two counties should fall solidly in his column. They were Sanders territory in 2016, and by comfortable margins. Back in 2008, they both went heavily for Barack Obama.

Winning here would bode well for Sanders in the weeks and months ahead in college town counties such as Pickens in South Carolina, Boulder in Colorado, Washtenaw in Michigan and Boone in Missouri. And that would bode well for his campaign as a whole. Counties like those were a key foundation of Sanders’ support in 2016.

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The eastern side of Iowa is more about small manufacturing than agriculture. And a trio of counties, Black Hawk, Linn and Scott are good places to watch the state’s blue-collar vote.

Those counties, home to Waterloo, Cedar Rapids and Davenport respectively, all sit above the state (and national) average for manufacturing employment. They are the state’s largest population centers outside of the Des Moines and University of Iowa areas.

Vice President Joe Biden wants to win these counties Monday night. These are the kinds of places were his Scranton, Pennsylvania roots should make a difference. Sanders won all three of these counties in 2016 and it wound up being a sign of his ability to reach beyond just young college-age voters. That was also true for Obama in 2008, who carried all three of these counties.

There is a lot of terrain like these counties ahead on the Democratic calendar, particularly in the Industrial Midwest — Pennsylvania, Michigan, Ohio and Wisconsin. They are important turf.

The biggest prize in the caucuses is Des Moines and its suburbs. Polk and Dallas counties are good places to see what might be thought of as Iowa’s big city, establishment Democratic vote.

Polk and Dallas are both above the state average for household income and college graduates. They are also growing much faster than the state as a whole. In that way, they are different from the rest of the state are in line with larger national urban growth trends.

These counties may be the biggest unknown for Monday night, and therefore the most crucial. They hold some markers on education and income that should make them good turf for Sen. Elizabeth Warren, but they also hold more traditional establishment voters that could place them with Biden. And a fragmented field could push Sanders over the top.

Big wins in these two counties were key to Hillary Clinton winning Iowa very narrowly in 2016. And Obama won them by tight margins in 2008 on his way to winning the caucuses that year. But again, watch the margins here. If the vote in Polk and Dallas is tight it may mean that urban/suburban, establishment Democrats are divided on their choices.

Away from the college towns and blue-collar hubs and urban areas, much of Iowa is more sparsely populated and driven by agriculture, particularly on the western side of the state in counties such as Fremont, Harrison, Lyon, Mills, Monona, Plymouth and Sioux. These counties can reveal something about the mindset of Democrats in the state’s rural centers.

These seven counties are all above the state average for agricultural employment and all have populations of less than 35,000 — most significantly less. Rural communities tend to be conservative, and every one of these counties voted Donald Trump in the general election in 2016. But remember the caucuses are tallying Democratic votes and in some of these communities that vote leans further left than one might expect.

These counties could be Sanders country Monday night. The Vermont Democrat won four of the seven in the 2016 caucuses. And in subsequent nominating contests, rural communities were a strength for him, showing something akin to a latter-day prairie populism. Monday will offer a hint of whether that trend may reappear in 2020.

Of course, Iowa is just the first contest in what could be a very long nominating process for the Democrats. Jumping to broad conclusions on Monday’s winner and losers may be a mistake. The picture will change as candidates drop out of the race.

But the patterns outlined here are worth watching. They’ll likely have meaning for the contests that, come post-Iowa. And after Monday night that’s where everyone’s attention will turn.