Democrats win majority in lower house
THE 2018 midterm elections are the first national vote since Mr Trump claimed the White House in his shock victory two years ago - and many see them as a referendum on his administration.
A few hours ago, CNN commentator Van Jones said the Democrats failure to take the Senate was "heartbreaking". He's in a slightly better mood now.
"It may not be a blue wave, but it's a rainbow wave," he said.
Mr Jones said the Democrats had become "younger, browner, cooler," with "more women, more veterans".
"We have the first Muslim women, first Native American women," he said.
"Something is happening out there."
This is the first time 100 women have elected to the House. Two Muslims are among them. The Democrats also boast the youngest ever Congresswoman, 29-year-old Alexandra Ocasio-Cortez.
The diversity push did not succeed everywhere, however. Notably, black gubernatorial candidates Stacey Abrams and Andrew Gillum both fell short.
All the major US networks are now projecting the Democrats have won the House.
That is a critical blow for Donald Trump. He will no longer be able to pass legislation without the support of his political opponents.
The Democrats will also gain control of important congressional committees, giving them the power of oversight over the White House. That means they will be able to investigate Mr Trump and his associates.
"He (Mr Trump) may feel good tonight," former Obama strategist David Axelrod told CNN.
"He's not going to feel good about it down the line.
"It really changes life in the White House, because you're constantly under scrutiny, subpoenas fly and you have to play defence in a way that you didn't have to before."
Republicans are having a very good night in the Senate.
Josh Hawley has beaten Senator Claire McCaskill to claim his party's third slipped seat of the night.
So, while losing the House, the Republicans have actually increased their majority in the other chamber of Congress.
Early Democrat hopes of a strong "blue wave" election were dashed, but they are predicted to win enough lower house seats to enable them to form a majority.
As expected, the Republicans look set to hold their majority in the Senate, with former presidential aspirant Ted Cruz holding off Beto O'Rourke in Texas.
With the flipping of the House to the Democrats, President Trump will now face an adversary with a great deal of power.
Trump is not expected to address the public today over the results.
The Republicans have retained the Senate majority while the Democrats have almost certainly won the House of Representatives.
White House press secretary Sarah Sanders admitted there was a "long night to go" as Republicans battle to retain their House majority.
"We feel good about where we are right now. Still, a lot of evening to go, maybe some early morning as well," Ms Sanders said.
She played down talk of a Democratic "blue wave", saying it would look more like a "ripple".
"Maybe you get a ripple but I certainly don't think that there's a blue wave," she said.
But with numerous media outlets suggesting Democrats will claim the House, Ms Sanders was asked if Donald Trump would call House Minority Leader Nancy Pelosi and offer to work with her if the chamber turns blue.
She suggested it was unlikely.
"I'm not sure why he would call Nancy Pelosi," Ms Sanders said.
She added Mr Trump's agenda would not change.
It's election day in the United States, and Americans have flocked to the polls in huge numbers to have their say in a vote that's been called a referendum on Donald Trump.
All 435 seats in the House of Representatives and 35 in the Senate are up for grabs in the midterms.
Democrats are hoping to win the 23 seats they need to seize a majority in the House. They need to gain two seats to take control of the Senate.
17 to go
The Democrats have picked up a seat in Colorado and one in Michigan. They are now 17 short of officially claiming a majority.
Some better news for the Democrats - Fox News now projects they will win control of the House.
They just claimed two more seats off the Republicans in Pennsylvania, and are currently leading in 31 other Republican-held seats.
They need to claim a total of 23.
Another crushing blow
Republican Mike Braun has defeated incumbent Democrat Senator Joe Donnelly in Indiana. The Senate is not going to flip today.
No 'blue wave'
The Democrats still expect they will gain control of the House, but this is not a victory on the scale many hoped for.
"This is not a blue wave. This is not a wave that's knocking out all sorts of Republican incumbents," CNN host Jake Tapper said as results continued to roll in.
"There is no tsunami," analyst Gloria Borger agreed.
"There's a lot of disappointment that I'm hearing.
"The excitement, the balloon is popping."
Some key results are going against the Democrats. They have failed to take congressional districts that were thought to be bellwethers, such as the sixth district in Kentucky. They continue to trail in the Florida Senate race.
There is a long way to go, but Donald Trump might be feeling relatively pleased right now, though some of the early senate results are clearly disappointing
Over in Michigan, Democrat Rashida Tlaib has become America's first ever Muslim congresswoman.
Democrat West Virginian Senator Joe Manchin was thought to be vulnerable, but he has been re-elected quite comfortably.
NBC projects Republican Andy Barr has won the sixth congressional district in Kentucky. We mentioned that as an important race to watch earlier.
Don't get overexcited or anything yet, but Democrat Beto O'Rourke is leading incumbent Republican Senator Ted Cruz in deep red Texas with about a third of the vote counted.
'It's a virtual tie'
That is a quote from CNN's Wolf Blitzer, referring to the sudden reversal of the Democrats' previously impressive leads in Florida.
In the governor's race, Republican Ron DeSantis has pulled ahead of Andrew Gillum. In the Senate, Rick Scott now leads incumbent Democrat Bill Nelson. The margins in both races are agonisingly thin.
There is better news for the Democrats in the House, where Donna Shalala just secured their second flipped seat. They need 21 more.
Here is what the national map currently looks like, courtesy of CNN.
You will notice a lot of red - that's because the Democrats' voters are concentrated in small urban areas, while the Republicans tend to win all the larger rural counties.
Good news for Trump
The high profile race to become Georgia's governor is not close at the moment, with Republican Brian Kemp leading Democrat Stacey Abrams 65-34.
Mr Trump and Oprah Winfrey each visited the state to support their respective candidates.
Meanwhile, the margins are tightening in Florida, where Democrat Andrew Gillum is suddenly only 900 votes ahead.
Here is the latest from Fox News' probability calculator. Red is Republican, blue is Democrat.
At the moment, nothing has happened to change the experts' predictions. It still seems likely the House will fall to the Democrats, while Republicans' control of the Senate is safe.
We have a result in Virginia's 10th congressional district, where Democrat Jennifer Wexton has claimed the Democrats' first flipped seat.
One down, 22 to go.
Polls have now closed in Ohio, North Carolina and West Virginia.
There are now 15 Democrats leading in Republican-held congressional districts. Remember, they need to pick up 23 to take control of the House.
The key races
Florida is the swingiest of swing states, so it is always a good barometer.
The Democrats' candidate for governor there, Andrew Gillum, is currently leading 52-48. In the Senate race, Republican Rick Scott is trailing Democrat Bill Nelson. Those numbers should worry, but not panic Mr Trump, given he won the state in 2016.
"The Democrats are pulling ahead significantly," CNN expert John King said.
There is much better news for the President in Indiana, where Republican Mike Braun is leading incumbent Democrat Joe Donnelly 58-38.
But Democrats are currently leading in five Republican-held House seats.
New York crowds nervous about results
It's packed at the polls, with lines stretching down the streets and voters saying the number of people out at the polls is twice what they've seen before, even at presidential elections.
Sherry Haddock, a 60-year-old fashion stylist at the NYU polling place near Union Square in Manhattan, told news.com.au she waited an hour to vote. "It's very busy," she said. "We need change.
"I'm trying to be positive but the last election I was very positive it would go my way and I was quite surprised."
At Public School 316 in Crown Heights, Brooklyn, people were reportedly leaving because there was a two-hour wait, with some machines broken.
The crowds could get even worse after work, with polls closing by 9pm in New York City. It's even earlier in other parts of the US.
A sensible voter
In such bitter, partisan times, this is a particularly refreshing attitude from New York voter Fernando Luciano.
Mr Luciano told our US correspondent Emma Reynolds he had voted for a mixture of Republicans and Democrats, and the most important factor for him was "transparency".