Washington (CNN) It could take a few hours -- or a few weeks -- to sort out who wins control of Congress after Tuesday's midterm elections .

But while results are flying in from all over the country beginning at 6 p.m. ET, we'll see indicators of whether Democrats will achieve the net gain of 23 seats they need to control the House , whether the GOP's two-seat Senate majority will grow or shrink and how key governors' races will shape up.

We tried to make it as easy as possible to keep track of it all. Here's an in-depth, hour-by-hour look at what to watch, and where:

The first polls close (6 p.m. ET)

Polls close at 6 p.m. ET in most of Indiana and Kentucky . Parts of both states are in the Central time zone, so it'll take time to see whether Indiana Democratic Sen. Joe Donnelly survives a challenge from Republican businessman Mike Braun.

The one we'll all be talking about first: Kentucky's 6th District. Amy McGrath, a former combat pilot, is challenging Republican Rep. Andy Barr.

It might not be a great national bellwether. In an unusual twist -- in part due to the brutal ads Barr has aired -- the race has largely become about McGrath and whether she is too progressive for the district, rather than a referendum on Trump or the incumbent congressman. But it will be an early indicator of the environment, and a Barr loss would give Republicans reason to panic.

Expect to see McGrath up early as the city of Lexington's results come in first -- but the margin is likely to tighten up quickly.

The early indicators (7-7:30 p.m. ET)

Democrats saw one more district in Virginia emerge as competitive late in the cycle: the 5th District, where former journalist Leslie Cockburn takes on Republican Denver Riggleman, an Air Force veteran and distillery owner. A Democratic win here would be a sign of a tidal wave threatening to wipe out Republicans whose races weren't even on the national radar.

The Atlanta suburbs feature two wave-maker districts -- if Democrats win either, it'd mean they're in for a big night. In Georgia's 6th District, Republican Rep. Karen Handel -- who won a ballyhooed special election against Jon Ossoff last year -- faces Lucy McBath, a challenger whose unarmed son was shot and killed over a dispute about loud music . And in the 7th District, Republicans are furious that Rep. Rob Woodall never took his race seriously. "If you don't think it behooves you to put paid media on air, we're not going to come help you. We're not a welfare organization," a Republican official said.

Also keep your eye on a few wave-makers in Florida . The Tampa-area 15th District is an open seat that emerged as competitive late -- so late, in fact, that Republicans couldn't afford a rescue effort. On the Atlantic coast side, the 6th District's open-seat contest for former Rep. Ron DeSantis' old seat is another potential Democratic pick-up that would suggest the party is soaring past the 23 seats it needs for a House majority. If either of Republican Reps. Brian Mast or Vern Buchanan lose, it's another sign that Democrats are on the path to winning the House.

History-makers. In In Georgia , the headliner is the governor's race between Republican Secretary of State Brian Kemp and Stacey Abrams, an emerging Democratic star who has combined a progressive platform with an appeal to black voters -- all with a chance to become the nation's first black female governor . If neither candidate tops 50%, the race will head to a runoff.

In Florida , a small portion of the panhandle is in Central time, so we'll need to wait an extra hour for full results to come in for the governor's race between Democratic Tallahassee Mayor Andrew Gillum, a progressive favorite, and DeSantis, who has aligned himself so closely with Trump that this is a potential preview of 2020.

Democrats' Senate must-wins. The The Florida Senate contest, with Republican Gov. Rick Scott challenging Democratic incumbent Bill Nelson, is one of the nation's most expensive and closely watched -- and if Nelson loses, it would severely diminish Democrats' shot at a majority.

A Midwestern state-level resurgence? Democratic former Consumer Financial Protection Bureau head Richard Cordray will try to win the Democratic former Consumer Financial Protection Bureau head Richard Cordray will try to win the governor's office in Ohio , a state Trump won by 9 percentage points in 2016. He faces Republican state Attorney General Mike DeWine. It's the first of several such tests for Democrats, who also hope to reverse GOP gains in Michigan, Iowa and Wisconsin.

The decisive hour (8 p.m. ET)

If you haven't tuned in yet, this is the time.

Control of the Senate on the line: The Senate majority could come down to two key races in states where the last polls close at 8 p.m. ET.

The most crucial hour for House control. This could also be the hour in which the next House begins to take shape. The two major battlegrounds are This could also be the hour in which the next House begins to take shape. The two major battlegrounds are Pennsylvania and New Jersey

In Pennsylvania , where the state Supreme Court made a mid-year decision to redraw the state's congressional district lines, Democrats look likely to pick up four seats -- the open 5th, 6th and 7th districts around Philadelphia, and the 17th District, where Democratic Rep. Conor Lamb and Republican Rep. Keith Rothfus were drawn together into the same suburban Pittsburgh race. One to watch as a sign of a Democratic wave: Whether Republican Rep. Brian Fitzpatrick, who represents Philadelphia's northern suburbs, holds on. If Republican Reps. Scott Perry (10th District) or Mike Kelly (16th District) start to sweat, it's a disaster for the GOP.

In New Jersey , Democrats need to win at least two races with two of their strongest recruits of the cycle: the open 2nd District, where conservative Democratic state Sen. Jeff Van Drew is the heavy favorite, and the 11th District, with Mikie Sherrill.

But it's the next two that would clearly show Democrats on their way to a huge House majority: Republican incumbents Leonard Lance and Tom MacArthur, one of the architects of the House's health care repeal bill who also backed Trump's tax bill, are also in the fights of their political lives. If MacArthur loses, it'd show how potent health care is as an issue for Democrats.

Democrats could also pick off House seats in Illinois . Sean Casten is their best bet -- he faces GOP Rep. Peter Roskam in the Chicago suburbs. Also near Chicago, Rep. Randy Hultgren faces a stiff challenge from Lauren Underwood, who campaigned with former President Barack Obama over the weekend. The 12th and 13th Districts are two more wave-maker types with GOP incumbents Mike Bost and Rodney Davis.

More key races to watch this hour:

-- Maine's 2nd District : Can Rep. Bruce Poliquin stave off Democratic challenger Jared Golden?

-- Mississippi Senate : Does Sen. Cindy Hyde-Smith hold off conservative Chris McDaniel and advance to a one-on-one runoff against Democratic former Rep. Mike Espy?

The majority makers (9 p.m. ET)

Suburban revolt? A slew of House seats are up for grabs in the 9 p.m. ET poll closings and, depending on which way states early in the night tilt, a Democratic House majority could come together based on poll closings in Texas, A slew of House seats are up for grabs in the 9 p.m. ET poll closings and, depending on which way states early in the night tilt, a Democratic House majority could come together based on poll closings in Colorado Minnesota and a dozen more states.

All eyes will be on Minnesota , where Democrats are now poised to turn the state blue two years after it came close to going for Trump in 2016. Democrats appear likely to hold the state's two Senate seats and the governor's mansion, but four closely watched House contests, including two where Democrats are on defense, will indicate how successful Democrats are in breaking down Trump's red wall.

The big question: Will either party gain House seats in Minnesota , or will it be a wash?

Democrats are confident in Minnesota's 2nd and 3rd Districts -- where Democrats Angie Craig and Dean Phillips are running against embattled Republican incumbents -- and Republicans have largely written off the two races. But Republican Jim Hagedorn in southern Minnesota and Pete Stauber in the northern reaches of the state are both on offense and party operatives are hopeful they can be two bright stops in what could otherwise be a tough night.

The poll closing at 9 p.m. ET could also cement 2018 as the year of the suburban revolt against Republicans. Republicans have all but written off Kansas' 3rd and Colorado's 6th districts, both suburban seats currently held by Republicans, but Democratic wins in suburban Dallas with Colin Allred, Houston with Lizzie Fletcher and Detroit with Elissa Slotkin and Haley Stevens could cement House majorities for Democrats.

History in Texas? Texas hasn't elected a state-wide Democrat since 1988. But Rep. Beto O'Rourke, fueled by Democratic enthusiasm and a Brinks Truck worth of cash, has given Sen. Ted Cruz a real race. Polls have the upstart Democrat down and Republicans believe the state's Republican tendencies will be evident on Election Day, but staggeringly high early voting numbers and national attention on the race have given O'Rourke a chance. A win here would be earth-shattering for Democrats.

Democrats hope that a loss in North Dakota (or earlier in the night) could be erased by a win in Arizona , where two congresswomen -- Democrat Kyrsten Sinema and Republican Rep. Martha McSally -- are fighting in a state Trump won in 2016.

The race has become a judgment on Walker, who is asking voters for a third term in the state, an ask that even Republicans admit makes his re-election difficult.

The dark horse gubernatorial race of the 9 p.m. ET hour is in South Dakota , where Republican Rep. Kristi Noem is in a surprisingly tough fight against Democrat Billie Sutton, an anti-abortion, pro-gun Democrat who is running to oversee a state that backed Trump by 30 percentage points in 2016.

Put the coffee on (10 p.m. ET and later)

Eyeing Orange County. If control of the House comes down to these hours, it's time to make more coffee.

Polls will close on competitive House races in Iowa Nevada and Washington state in this two-hour span -- all states where Democrats believe it is likely they will pick up seats -- but the biggest prize of these late-night hours comes from California , where at least nine House races up and down the state are worth watching.

An important note: If Democratic control of the House comes down to California, the country is in for a long ordeal. California is notoriously slow at counting votes, meaning races could be decided in days and weeks, not hours.

While Democrats are fighting in competitive races throughout California's Central Valley -- where Democrats Josh Harder and T.J. Cox are looking to oust Republicans in districts Clinton won two years ago -- the bulk of Democratic focus will be on Southern California, namely the Los Angeles and Orange County area.

Katie Hill, Gil Cisneros, Katie Porter, Harley Rouda and Mike Levin are the five Democrats looking to flip seats in the traditionally Republican area. Depending on how races earlier in the night go, these five seats in Southern California could either be the cherry on top of a good night for Democrats or the focus of considerable attention over the next weeks.

Nevada and Montana Senate contests. The most hotly contested races, though, are in The most hotly contested races, though, are in Montana , where Democrat Jon Tester is looking to hold onto his seat against Republican Matt Rosendale, and Nevada , where Democrat Jacky Rosen is on offense against Republican incumbent Dean Heller.

Democrats expect to hold Montana, where Tester is running on his connections to the state and authenticity , but Nevada is expected to be a fight, despite that fact that Heller for months has been seen as the most vulnerable Republican incumbent running for Senate this year.

Governors' races wrap with a late night in Alaska. Democrats are looking to flip gubernatorial seats in Nevada, where Democrat Steve Sisolak and Republican Adam Laxalt are fighting over the governor's mansion currently held by Republicans, and Iowa, where Democrat Fred Hubbell is looking to oust Republican incumbent Kim Reynolds.

A win by either Democrat would cement each as a key figure in the 2020 presidential nomination fight; both Nevada and Iowa are key early states.

The most unexpected race of the night could be in Alaska , where the current governor, independent Bill Walker, ended his re-election campaign in October to back former Sen. Mark Begich, the Democratic candidate running against Republican Mike Dunleavy. Republicans believe the race will be an easy pick up for them, but the lack of reliable polling and unexpected withdrawal of the current governor has a chance of delivering a late-night surprise.

Correction: This story has been updated to correctly state that Trump lost the state of Minnesota in 2016.