Republicans have lost control of Congress following the United States midterm elections, with Democrats securing majorities in both the House of Representatives and the Senate.

Public Policy Analyst Dr Marius Kudumo says the outcome places constraints on Trump's ability to advance his legislative agenda, as he will face an opposition-controlled Congress for the remaining two years of his presidency.

According to preliminary results, Democrats secured 228 seats in the House, compared to 139 for Republicans, while 68 races remained uncalled. The results available at the time covered 367 of the 435 seats.

In the Senate, Democrats and their aligned independents secured 54 seats, while Republicans had 44, with two seats not accounted for in the reported figures.

Before the election, Republicans held 218 seats in the House, compared to 214 for Democrats, while in the Senate, Republicans held 53 seats, while Democrats and their aligned independents held 47.

A party needs at least 218 seats for a majority in the House and 51 seats in the Senate.

"The results indicate that there has been a shift of power. You are having the Democrats controlling both houses. But basically, elections in a constitutional democracy are about reward and punishment. In other words, if the governing party is doing well, they will re-elect that party. But if there are concerns from the voters, they will punish you. That's basically what's happening there. But power has shifted to the Democrats."

Some international media houses reported that the Iran conflict could have contributed to the outcomes of these elections, while some said it was influenced by public dissatisfaction with the current US economy and the cost of living. 

"Your average American voter is not concerned about foreign policy. They are more concerned about domestic issues. Currently, in the States, as in the rest of the world, there are issues of high cost of living. There are also issues of higher fuel prices. And there are also issues with these tariff policies, basically, how they affect them. These are the considerations of the voters. And if you look into these elections, there are certain blocs that voted for President Trump, but they have shifted this time around."

The new Congress is scheduled to begin its work on 3 January next year. Democrats will then take control of both chambers and lead congressional committees, giving them authority to scrutinise the Trump administration.

However, he says Democrats will face limits in advancing their agenda as  Trump remains president and retains the power to veto or reject bills passed by Congress.

"With this election, we are expecting that there will be constraints in terms of what the executive can do. We are also hoping that there might be a scale down on some of the legislation, because if there are new legislations, for example, they have to go through these houses, and these houses, because of their composition, might scale down, like when President Trump was actually dominant."

US midterm elections are held halfway through a president's four-year term. 
The next presidential election is scheduled for November 2028.