For Canadians watching U.S. President Donald Trump’s second term unfold from across the border, the United States’ midterm elections could become an important turning point. The Nov. 3 vote will not decide who occupies the White House, as the next presidential election will be in November 2028. Instead, Americans will decide who controls the U.S. Congress, and that balance of power could affect everything from tariffs and trade with Canada to how much room the president has to pursue his agenda. Here’s what Eric Ham, CTV News’ political analyst in Washington D.C., told CTVNews.ca in an interview about what Canadians need to watch for in the U.S. midterms. What are the midterm elections? Midterm elections are held halfway through a U.S. president’s four-year term and take place every two years. Americans will vote for all 435 seats in the U.S. House of Representatives, where members serve two-year terms. In the U.S. Senate, which has 100 seats and six-year terms, roughly one-third of the seats are contested every two years. “So you have the presidential election, which of course are the major elections that we see take place in the United States every four years,” Ham said. “And then ... we have what are called off-year elections ... that are two years after the presidential election, which also determines the balance of power in Congress.” When can Americans vote? Election Day is Nov. 3, but Americans do not necessarily have to wait until then. Voting rules vary by each individual U.S. state. Many offer early in-person voting and absentee or mail voting, with the timing and procedures determined under state election laws. “Elections actually take place at the behest of states,” Ham said. “It is states that control its own elections.” That means Canadians may see U.S. voting begin weeks before election night, depending on the state. Why does control of Congress matter? Congress, made up of the House and Senate, plays a central role in passing legislation, approving spending and exercising oversight of the executive branch. That makes the midterms particularly significant during a presidency in which Trump has pursued major changes to U.S. trade and foreign policy. A party controlling both chambers has greater ability to advance its legislative priorities. A divided Congress can make it more difficult for the White House to get legislation through. Ham said the question for Canadians is not simply if Democrats gain seats, but whether they gain enough power to challenge the president on issues such as tariffs. “Much of that is going to be determined by who controls Congress,” Ham said. What could happen to Trump’s tariffs? Trade is one of the biggest interests for Canadians in this election, because the U.S. is Canada’s largest trading partner. If Democrats gain control, lawmakers could seek to reclaim some of the authority the current Congress has delegated to the executive branch over trade. However, in case that happens, Ham said, “the fact that Congress will now pass legislation that will either rescind Trump’s tariff authority or will take back that authority for themselves, there’s no guarantee the president is going to go along with that.” What should Canadians watch on election night? For Canadians, Ham believes two things will be particularly important. “One: how wide a margin are we going to see if in fact Democrats take back control of both chambers,” he said. ”The second thing they need to be watching for ... is what will be the response to these elections if Democrats do take back both chambers,” highlighting the size of any change in congressional power and what happens afterward.