Midterm elections: What does the Democrats’ win in the House of Representatives mean for US politics?

What powers have the Democrats won and how can they use them?

The long prophesied “blue wave” was not the tsunami the Democrats had hoped for, but the party did successfully wrest control of the House of Representatives, bringing an end to the triple-headed Republican power-hold in Washington DC.

The Democrats gained over 30 seats in the House to give them their first majority since 2006, during George W Bush’s second term, and which was lost in 2010 two years after Barack Obama took office.

The win installs a wave of diverse, progressive, first-time candidates in Congress, and the party immediately plans to take advantage of their newfound powers, which include being able to subpoena Donald Trump, relaunch probes into his 2016 presidential campaign and launch fresh investigations into his administration.

Democrat preparations for action in case of winning the House have reportedly been underway for months.

But the Republicans clung on to the Senate – the upper house – in an election that saw them defending nine seats – far fewer than the Democrats’ 26 which were up for grabs.

The Democrats may be in a stronger position than they have been in Congress for eight years, but without majorities in both congressional houses they will still struggle to block many of the Trump administration’s political moves.

With the Senate still on his side, Mr Trump will retain his ability to appoint his picks to the Supreme Court and Cabinet.

Nonetheless, the shift means Donald Trump could be forced to use diplomacy if he wishes to push through major pieces of legislation. Having spent his political career aggressively disparaging the opposition, the power shift could force the president to reassess his methods.

What can the Democrats do now they control the House?

Impeachment

With a Democrat majority there is likely to be a surge in investigations into the president’s numerous scandals and controversies – the party will have more money, staff, and control over the chamber’s committees. It is possible they could pursue formal impeachment action against Mr Trump, but there are major caveats and obstacles.

The House of Representatives can instigate impeachment proceedings, but it requires a majority House vote. With a Democrat majority, that is now much more likely, though many Democrats would be cautious about taking such action as historically such a move has generated a voter backlash.

Even if the House did take impeachment action, two-thirds of the Senate would then have to vote in favour of it, and the Republicans have strengthened their control of the Senate, making impeachment unlikely to be successful.

It is also thought Democrats are unlikely to make any serious moves towards impeachment until Robert Mueller’s investigation into election interference and possible collusion between Russia and the Trump campaign is complete.

Tax returns

Ever since Mr Trump announced his intention to run for president, his decision not to release his tax returns has been a major bone of contention.

Pursuing the elusive documents is said to be a top priority for the Democrats following their electoral success.

Representative Richard Neal, who is expected to lead the House Ways and Means Committee, told CNN in October he plans to first ask Mr Trump for them. Mr Trump has been asked to hand them over in the past, and has refused, but Mr Neal has said if the president does not hand them over, he will use an arcane IRS code to formally request them, a move expected to launch a lengthy legal battle.

But the documents could then be examined to see if Mr Trump had any business ties with Russia that could have led to Russian interference.

Russia

Speaking of Russia, a Democratic House could reopen the congressional investigation into Mr Trump’s relationship with Russia, which the Republican-led house closed in March. A reopened investigation would be informed by Mr Mueller’s ongoing probe, and would likely seek to go after any unanswered questions from that investigation in order to reveal more and put further pressure on the president.

Mexico border wall

In order for spending bills to be enacted, they need to be passed by both the House and the Senate. With a Democratic-controlled House, any Republican efforts to secure funding for a US-Mexican border wall could be blocked from passing.

The Republicans have said they are “committed” to ensuring they secure the funding for the president’s signature election pledge, but Democrats have signalled they are willing to fight border funding.

In August Mr Trump said he was looking for about $5bn (£3.8bn) in funding “for this coming year”, adding: “We’re building the wall, step by step.”

In March, Congress allocated $1.6bn (£1.2bn) in border spending – a portion of which will go towards replacing sections of existing border walls.

Healthcare

The two key issues on voters’ minds for the 2018 midterms appeared to be immigration and healthcare, with the Democrats running a strong campaign on protecting elements of improved affordability of healthcare insurance installed by the Obama administration.

The Democrats’ House leader Nancy Pelosi said after the midterms the party would focus on fighting to protect Medicare and Medicaid – long running programmes to provide health insurance to over-65s and disabled people regardless of income.

Democrats have also said they want to lower drug prices and health cover premiums and aim to protect Americans with pre-existing conditions from higher insurance premiums.

Dismantling Mr Obama’s health reforms have been a key aspect of Mr Trump’s legislative programme, but he struggled even to convince his own party that removing Obamacare in its entirety was a good idea.

Iran

Democrats were enraged by Mr Trump’s withdrawal from the international nuclear deal with Iran brokered by the Obama administration in 2015. But even with a House majority there is little they can do to change the policy as long as Republicans occupy the White House.

US politicians are also wary of seeming too friendly to Iran, especially given hostility to Tehran by the government of Israel. While Israeli Prime Minister Benjamin Netanyahu has worked increasingly closely with US Republicans, strong ties to Israel remain a top priority for both parties.

Trump’s future ambitions

Donald Trump has already registered his 2020 campaign slogan as “Keep America Great”. Is the Democrat House win a setback to his presidential ambitions?

Losing control of the House, is entirely in keeping with recent US political history and is unlikely to spell disaster for Mr Trump in the coming years.

Most presidents who lose one or even both houses in their first midterms go on to re-election – including Barack Obama, Bill Clinton and Richard Nixon.

Herbert Hoover was the last president who lost a majority in Congress during his first term and then lost re-election – and that was in 1933 as the US was picking up the pieces of the stock market crash. But today’s US economy is in comparatively rude health.