Much of the current buzz in US politics has been around imminent midterm elections. As the name suggests, these are elections that take place half-way through a presidential term, giving Americans something more to do than simply celebrate or lament Donald Trump’s two-year anniversary in power. Yet the midterms, along with having many other crucial effects on the American political scene, will strongly influence how the president’s next two years progress, as well as perhaps whether he wins another four after that. There is a lot on the line this November.

At the midterms, many key positions will be contested. Democrats, Republicans and independents will battle to become state governors, as well as representatives and senators in Congress. Because the US president is not a member of Congress (unlike in the UK where the prime minister has to also be an MP), presidential and congressional elections can be held separately. While all positions have a 4-year term, elections to them are staggered, with some held in the same year as the presidential election and others – the midterms – held two years later. At these midterms, all 435 seats in the House of Representatives, along with 35 of the 100 Senate seats will be voted on. It is, of course, the people in these positions who will vote on the legislation put before the country in the coming years. This is not even to mention the 39 governorships up for grabs, which will decide the futures of the individual states in question, and may provide huge boosts to the political careers of the victorious candidates.

Donald Trump will be watching these votes closely for a number of reasons. While each electoral battleground has its own key issues and demographics affecting the outcome of the midterms, such votes are invariably also understood as an unofficial poll on a sitting president’s popularity. The electorate can only process so much political information, and will naturally look to a party’s most prominent figure as a guide to whether that party will do them good or not. Trump is of course the most-high profile republican politician, so if voters think he is doing poorly in office, they will be far more likely to punish his party at the voting booth. Big Republican losses will surely spell trouble for the already volatile Trump administration.

Trump will also have to work with whatever Congress is returned by the election. He may have enjoyed a Republican majority in both the House and the Senate, but his job may be much harder if one or both houses are won by the Democrats. In such a case, Trump may find his ability to pass laws greatly hindered and will have to either water down or completely abandon some of his more controversial legislation.

And of course, there is the elephant in the Oval Office: the Russia investigation. Special counsel Robert Mueller and his team have been investigating any collusion Trump or his campaign team may have had with Russians aiming to interfere with the 2016 presidential election. Whether or not Mueller finds anything to directly link Trump to the interference remains to be seen, but if anything damning is discovered, the path to the president’s impeachment is far clearer if the Democrats are dominant in Congress. The House needs to pass a simple majority vote to bring a case of impeachment against the president before it is heard by the Senate, where a two-thirds majority is required for the president to be removed from office. It is consequently unlikely that Trump will be impeached even with two democratic houses, but it would certainly make initiating the proceedings against him easier. As with Bill Clinton’s presidency, even an unsuccessful impeachment hearing could come to define the rest of Trump’s term and his ultimate legacy as president.

It is very easy, though, to get ahead of ourselves. As it stands the Democrats stand a slim chance of taking both houses of Congress. Although Trump and his party are not supremely popular in the country, and may very well lose the House to their Democratic rivals, the Senate may prove a very different proposition. Although a large number of the chamber’s seats are up for re-election, most are already held by Democrats, giving them little opportunity to win much ground. Democrats therefore have to make significant gains in traditionally Republican states while themselves holding off Republican attacks in states they hold, many of which backed Trump in the 2016 election. This is not to say that the midterms will necessarily be positive for Trump, but it is unlikely to spell the end of his administration’s influence.