5 reasons why Democrats might not take control of Congress in U.S. midterms

A voter arrives to cast their ballot during early voting for the midterms in Pontiac, Mich., on Saturday. Michigan is one of many states where the margin of error in polling means the Senate race is too close to call. (Brian Snyder/Reuters)

Even with Trump's deep unpopularity, Democrats face steep climb

Political strategists of both main parties in the U.S. believe it’s almost certain the Democrats will take control of the House of Representatives from the Republicans in Tuesday's midterm elections.

The likelihood of the Democratic Party flipping the Senate, however, is another story.

In the House, non-partisan election-forecast websites such as Cook Political Report rate the Republicans as vulnerable in as many as 30 GOP-held seats. The Democrats need a net gain of merely three to get a majority.

Also, consider that the party of the sitting president has suffered a net loss of House seats in all but two midterm elections since the late 1930s, and that no U.S. president has gone into a midterm with a lower approval rating than what Donald Trump has right now.

But when it comes to the Senate, there are doubts the Democrats have a clear path to flipping the four states they need to reach the majority threshold of 51.

Here are five reasons why the Democrats may not wind up with control of both houses of Congress for the remainder of Trump‘s time in office.

WATCH | What a Democrat sweep of the midterms would mean for Trump and the GOP:

With the 2026 U.S. midterm elections threatening Republican control of Capitol Hill, CBC’s Ellen Mauro breaks down how a shifting balance of power could challenge President Donald Trump’s agenda — and the key tools he can use to counter Democratic opposition.

1. The 2026 Senate map is tough for Democrats

Flipping the Senate this year was always going to be a tough haul for the Democrats, simply because of their limited opportunities to gain seats in this particular midterm.

Only one-third of Senate seats are up for grabs each election, because senators are elected to six-year terms.

Nearly all of the Republican-held seats the Democrats are seeking to flip are in states that Trump carried by at least 11 percentage points in 2024. (The only exceptions within easier reach are Maine and North Carolina.)

That means to get a majority, the Democrats must gain at least two states from a list that includes Ohio, Iowa, Texas, Alaska and Kansas.

That will require a giant swing toward the Democrats in states that have long been ruby red.

WATCH | Why Trump looms so large in the Texas race for U.S. Senate:

Texans have voted Republican for decades, but as many sour on the Trump agenda, Democrat James Talarico could flip the state's Senate seat. For the National, Paul Hunter talks to voters on both sides to see if the race is now a referendum on Donald Trump himself.

2. The polls could be off

There's been a well documented history of polling in the Trump era failing to measure the full extent of support for Republicans. On the final weekend before the 2024 presidential election, a poll in Iowa (by a pollster with a sterling reputation) showed Kamala Harris up by three points. Trump won the state by 13.

Polling firms have, over the years, adjusted their methods to try to compensate for the tendency of Democrats to be more likely than Republicans to answer polls.

They weight responses so samples better reflect the full demographics of who actually shows up at the polls, factoring in education, income and ethnicity. They ask respondents who they voted for in the last election to check the sample isn’t torqued toward one party or the other.

Polling is a science, but an inexact one, and it’s important to remember its limitations. One key limitation is that when two candidates are polling within the margin of error — say, a lead of just two percentage points — you really can’t say who’s winning.

Recent polls in the Senate races in Maine, Michigan, Ohio and Kansas have all shown results within the margin of error.

WATCH | Two Blocks from the White House answers your questions about the midterms:

3. So much depends on turnout

Voter turnout in midterm election years has historically lagged behind turnout in presidential election years. The key midterm challenge for each party, whether on the offensive or defensive, is getting their supporters simply to show up.

While polling broadly suggests registered Democrats are more enthusiastic about punishing Trump than the Republican base is defending him, Democratic candidates still need help from independent voters to win in toss-up races.

It's worth noting that the highest turnout for a midterm election since the First World War came in 2018, during Trump's first term.

One factor that could dampen a blue wave is whether the Democratic Party and its candidates made strong enough arguments for why Americans should vote for them, rather than simply relying on their desire to vote against the Republicans.

WATCH | 'Double haters,' fed up with both parties, could sway tight midterm races:

In states like Arizona, some undecided voters have grown to dislike both major political parties. Rather than withdrawing altogether, these ‘double haters’ remain politically engaged and their votes could swing the U.S. midterms.

4. GOP money has flooded the airwaves

Extraordinary amounts of money have gone into campaign advertising this midterm cycle.

In just the competitive Senate races, Republicans and their affiliated political action committees (PACs) have spent some $1.2 billion US, outpacing Democrats by $237 million US, according to a Bloomberg analysis of ad-buying data from the consulting firm AdImpact.

Elon Musk alone has spent the staggering sum of nearly half a billion dollars supporting Republican candidates in the midterms ($475 million US, reports the New York Times, $446 million US, according to the Guardian.)