The November 6 midterm election was a very good one for the Democrats.

Next year they will have far more power in US politics, and the Republicans far less. The way Democrats won, and the Republicans lost, should worry President Donald Trump for it suggests he is going to have a hard time getting re-elected in 2020. There are two main reasons why:

The margin of victory

In what was a very high turnout election, Democrats beat the Republicans by 7.1 points in the popular vote. In 2016, Hillary Clinton’s margin was just 2 percentage points. So this was a five-point decline from what was already a low 2016 number. It was on par with other recent midterm “wave” elections which had margins of 7.1 for the Republicans in 1994; 8.0 for the Democrats in 2006; 7.2 in 2010 and 5.7 in 2014 for the Republicans.

And it was enough to give the Democrats the House of Representatives, win seven governorships, and pick up 330 state legislative seats. Even in the Senate where Democrats lost ground, they won the popular vote in those races by 15 points (they got 57% of the popular vote; the Republicans — just 42%).

In the exit polls taken last night, Trump’s approval rating was 44 favourable, 55 unfavourable. This is consistent with the voting results showing him and his party losing ground since 2016. The reason this matters, is that if Trump is any lower than he was in 2016 — and he looks to be between 2 and 5 points lower — he will not get re-elected.

The GOP lost ground in critical 2020 battlegrounds

Democrats had strong nights in both the Midwest/Rustbelt region and in the Southwest part of the US, the regions of the country which will decide the 2020 presidential election. In the Rustbelt/Midwest Democrats won Senate races in Pennsylvania, Michigan, Minnesota, Ohio and Wyoming by large margins; and also won governor’s races in and Michigan and Minnesota by very large margins.

Democrats will pick up between seven to nine House seats in this region, and while they came up short in the Iowa governor’s race, they now control three of the four House seats there. As this was the region that was seen as one which gave Trump the presidency, the deep rejection of the GOP there has to be seen as a dangerous development for the president.

The Southwest, on the other hand, has never been friendly territory for Trump. The three states which saw the biggest movement towards the Democrats in 2016 were California, Texas and Arizona.

The midterms saw Beto O’Rourke make a statewide race in Texas competitive for the first time in decades. The Arizona Senate race is too close to call and Democrats won all the important races in Colorado, New Mexico and Nevada. Dems are on track to gain 11 House seats in these states including California, a state where the GOP didn’t even have a Senate candidate on the statewide ballot this year. All of this adds up to a night of dangerous erosion for the Republican Party in the region of the United States with the two biggest states, California and Texas.

Over the last two years there was always this sense that while the president’s thunderous championing of white nationalism and anti-immigrant rhetoric and policies was hurting him in the heavily Mexican-American parts of the southwestern US, it was the key to unlock the Rustbelt and Midwest — the part of the country seen as the one which gave him the presidency.

Given the really bad night the GOP had in the northern part of the US, that no longer appears to be true, which is a highly problematic development for him and his party. He may have used the migrant caravan in the final days to win in very red and rural places like Indiana, Missouri and Tennessee but in the states which matter for him to get re-elected next year, there is far more evidence that his attacking immigrants has done far more to hurt his re-election chances.

So yes, during his post-midterms press conference on November 7, Trump tried to claim that the 2018 election was a good one for him. But in reality, it wasn’t — it was a bad loss, a repudiation; the real weakness evident in the two parts of the country where he needs to win to get re-elected suggests Trump will just be a weakened president over the next two years. Today, his chances for re-election look much more difficult than they did just a few months ago. — Al Jazeera