WASHINGTON—$5,000 for every American adult. An $8 billion bailout for farmers. $90 payments for seniors. President Trump is relying on a new strategy to salvage Republican seats in the midterm elections: promising an array of financial benefits to Americans, some of which he said he would only deliver if his party defies the polls and keeps control of Congress.

The president started his campaign to put cash in the pockets of voters during Republicans’ midterm convention in September, when he announced a $1 trillion proposal to send $5,000 to each adult citizen—if the GOP holds on to its congressional majority. Since then, Trump has sent $90 to Medicare recipients to offset premiums and $500 checks to nearly one million people for what the administration called excessive fees under the Affordable Care Act.

On Monday, Trump said he would send $8 billion in direct payments to U.S. farmers, some of whom have soured on the president amid his tariffs and as prices for diesel, gasoline and fertilizer have risen since his war with Iran. And on Tuesday, the president announced a new program that would provide up to $30,000 to Americans if they report a tip about government fraud. The White House is also discussing rolling out executive orders in the remaining days before the midterms aimed at addressing high prices, including one focused on reducing housing costs, according to people familiar with the matter.

Republicans are facing one of the toughest midterm environments of any party in years, and the series of policy announcements serve as both an effort to motivate voters and a tacit acknowledgment that people are hurting financially.

Democrats have accused the president of trying to buy votes. Davis Ingle, a White House spokesman, described Trump as the “unequivocal leader, best messenger, and unmatched motivator for the Republican Party,” and said that “the choice has never been clearer: doubling down on President Trump’s winning, common-sense agenda or the Democrats’ extreme liberal policies and obstruction.”

The pledges get cheers at rallies where Trump supporters don red hats and wait in long lines to get a prime spot, but it is unclear if they will turn out the voters that Republicans need, those who vote conservative but tend to stay home during elections when Trump isn’t on the ballot.A Wall Street Journal poll last month found that voters aren’t sold on Trump’s proposed $5,000 checks, with 64% of respondents calling it a bad idea.

Trump outlined the $8 billion farm bailout during a rally Monday in Kansas, telling his supporters that the Agriculture Department would launch a “Harvest Fuel Relief program” that would help offset rising diesel costs as farmers harvest their crops.“And when the Republicans win, we will pass even more funding for our farmers,” Trump said at the rally.

Trump also said he would sign legislation permitting the year-round sale of gasoline blended with 15% ethanol, a long-sought-after policy by U.S. corn growers. Congress has to first pass the legislation, which faces an uphill climb. Trump said he would only agree to the policy if Republican Sen. Roger Marshall wins in Kansas against Democratic opponent Adam Hamilton.“With Roger Marshall in the Senate, we will make year-round E-15 permanent,” Trump said.

“But if Adam Hamilton is in, I’m not doing it.”

The president has also made several announcements about new projects that are intended to benefit states that will help determine which party controls Congress. The president last week wrote on social media that Taiwan had committed to buy natural gas from a proposed export terminal in Alaska.

And he highlighted a Minnesota company’s plan to build a $15 billion steel mill in Iowa. During a House Finance Committee hearing in September, Treasury Secretary Scott Bessent answered questions about President Trump’s plan to pay each adult citizen $5,000 if Republicans win the midterm elections. Photo: Graeme Sloan/Bloomberg NewsSome of the benefits have already been distributed to voters. The $500 Affordable Care Act refund checks went out on Oct. 1 (alongside a letter touting his record on cutting healthcare costs), and the $90 payments to Medicare recipients were deposited in bank accounts or sent out on Oct. 8.

But the president’s proposal to dole out $5,000 checks to Americans, which Trump has said would be contingent on the GOP keeping control of Congress, is expected to face hurdles. Democrats and some Republicans have expressed skepticism, raising concerns that such a move would balloon budget deficits and fuel inflation. Sending $5,000 to every American adult would likely cost well over $1 trillion, the Journal has previously reported. The federal government has made direct payments to Americans in the past.

In the 2020 election, as Trump was running for re-election and the Covid pandemic ravaged the country, the government sent out $1,200 checks to tens of millions of Americans that arrived signed by Trump with letters from the White House taking credit for a bipartisan deal passed by Congress. In 2022, then-President Joe Biden said he would forgive up to $20,000 in federal student loan debt for tens of millions of Americans. Conservatives dismissed the move as an attempt to win over young voters ahead of that year’s midterm elections.

Democrats lost nine seats in the House and gained one seat in the Senate. Democrats say Trump’s proposals won’t move the needle in this year’s midterms, where concerns about affordability are top of mind for voters.“Nobody’s buying it, people don’t even believe he’s going to come through on it. The problem with breaking your promises repeatedly is that nobody believes a damn thing you say,” said Jared Leopold, a Democratic campaign consultant.

Trump has previously made similar promises to send cash to Americans that haven’t materialized. Early on in his term, he said he wanted to give 20% of savings from Elon Musk’s cost-cutting initiative. Then, as he imposed tariffs on several nations and escalated a trade war, he said several times that he wanted to send a $1,000 or $2,000 tariff dividend to most Americans.

The president has also recently emphasized his own financial investment in the midterm election. In a social-media post Tuesday, Trump said he would spend more than $400 million dollars to help Republicans in the midterms. The president didn’t specify where that money would come from, but MAGA Inc., a super PAC aligned with Trump, had nearly $416 million cash on hand at the end of August.“It is my Great Honor to do so on behalf of the Republican Party, which has done so much to bring our Country back from the Edge of Oblivion,” Trump wrote.

Write to Marianne LeVine at marianne.levine@wsj.com and Natalie Andrews at natalie.andrews@wsj.com