Voters in the United States are angry.
Sarah Smith, BBC North America editor in Washington DC. si.
Even the most optimistic Democrats did not expect to achieve such impressive results. By winning stunning victories in areas long considered Republican strongholds, they took control of both houses of Congress.
Everyone prepared themselves to wait a long time, maybe a few days, to find out who would take over the Senate. But the magnitude of the Democrats' victory made it possible to announce this victory before midnight (US time).
If the Democrats win in one of the states of Iowa or Ohio and maybe Texas or Kansas, it will be an amazing event; But winning all four countries is amazing.
The reason for this is quite clear. Voters across the United States are angry about the cost of living, and they blame Donald Trump. They believe that his decision to start a war with Iran as well as his trade tariffs caused the price increase.
Donald Trump wrote on social media: "My name was not on the ballot; if it had been, we would have won by a huge margin (decisively)! For weeks he asked his fans to act as if he were a candidate. Putting himself at the center of the Republican election campaign, at a time when his popularity was at an all-time low, was a very risky move that seems to have backfired.
Now he says he will become "Mr Veto". He can use his presidential veto power to prevent bills passed by the Democrat-controlled Congress from becoming law.
But on the other hand, Democrats can now block any legislation they want. They could also launch a congressional investigation into some of his most controversial decisions, as well as the ways he and his family have profited since returning to the White House.