The economy brought Trump back to power. Now it's his downfall

As President Donald Trump campaigned for the nation's highest office in 2024, he regularly blamed Democrats for the country's economic anxiety.

During campaign stops across the U.S., Trump frequently asked voters if they were better off than they were four years prior. At the time, his message appeared to land: In an election centered on inflation and the cost of living, Trump won every swing state and the nationwide popular vote.

Two years later, voters grappling with those same kitchen-table issues took away much of his party's power in Washington and in states across the country.

Democrats rode a blue wave of historic proportions in Tuesday's midterm election to flip everything from battleground congressional seats to long-held Republican governorships. The Democratic Party will now have control of both the House and Senate, ending the Republican Party's trifecta of power in the federal government.

Nearly nine out of 10 voters in the CNBC Voter Poll said the cost of living was a crucial or major factor in their vote for Congress. Participants in the poll ranked the economy as the most important issue facing the country during the midterm election, ahead of topics like the state of democracy and immigration. Three out of every four survey participants rated the economy as "poor" or "not so good," compared with just 2% who described it as "excellent."

And perhaps most telling of all: Fewer than one out of every five voters said their family's financial standing was better than it was two years ago.

Much of their dissatisfaction was centered on Trump himself, with about two out of every three voters saying his policies worsened economic conditions in the country.

"It was all about the economy," said Mark Zandi, chief economist at Moody's Analytics. "Most Americans are struggling with the high inflation and have been for quite some time, and they're just angry."

Tuesday's election played out against the backdrop of a war with Iran that has been politically unpopular and exacerbated the inflationary pressures facing everyday Americans. The CNBC Voter Poll found nearly three out of every four people said the war was a crucial or major factor in their vote for Congress.

Trump told Fox News that voters were presumably unhappy with the surge in gas prices, even if they generally agreed with the need for military action against Iran. Vice President JD Vance said on social media that some voters who backed him and Trump in 2024 likely supported Democrats in the midterms as a result of the war.

U.S. drivers paid about $4.15 for an average gallon of gas on Tuesday, the highest of any midterm or presidential election day since at least 2000, according to AAA. Gas prices have surged about 37% over the past year as the Middle East conflict crippled the global crude trade.

"America sent a very clear message," said Patrick De Haan, head of petroleum analysis at GasBuddy, a fuel price tracking platform. "Going into an election with prices that on Election Day have never been higher is something that garners a lot of frustration from consumers."