Trump keeps promising checks to Americans. Polls show voters may not be buying it.

Giving out checks to Americans has emerged as one of President Trump's major messages in the final weeks of the campaign season.

But Americans are skeptical, as multiple polls show voters harbor serious doubts about whether Trump will deliver and whether the cost would hurt the economy.

The president is nevertheless determined to escalate the issue with 29 days until the midterm elections. This past weekend, he mentioned checks at every campaign stop and made a new pledge to send $90 to millions of seniors enrolled in Medicare Part B.

The payment is intended to offset October Medicare premiums and will be deposited this month, but Trump emphasized that it will come in the form of cash.

"Over 20 million seniors on Medicare will soon be receiving a deposit of nearly $100 directly into their bank accounts," he announced on Truth Social . "You'll get your money almost immediately."

The Trump administration also began sending out $500 checks to about 950,000 Obamacare enrollees at the beginning of this month , with Trump again repeating his much bigger promise of $5,000 checks to adult Americans if Republicans sweep the midterms.

"Presumably the primary activity of the Office of Management and Budget is currently to scour every account in every agency to find loose change that can be sent out prior to the midterm elections," Douglas Holtz-Eakin, president of the American Action Forum and a longtime Republican economic aide, quipped in response to the flurry of promises.

"Let's see what they find this week," he wrote in a note on Monday.

In poll after poll, the issue is gaining little traction with key persuadable voters.

A recent Economist/YouGov survey found that only 21% of registered voters felt that Trump would definitely or probably follow through on his $5,000 check promise, against 57% who doubted he would actually deliver.

Another NBC opinion poll last month asked voters whether a midterm candidate supporting the plan would make them more or less likely to support that candidate. Just 21% of respondents said it would make them more likely, compared with 46% who said it would make them less likely; 33% said it would make no difference.

The Marquette Law Poll of Wisconsin found that 70% of residents of the Badger State oppose the checks altogether, and 59% said they would hurt the economy.

The checks have also become a focus for Trump opponents, with a protester outside a recent presidential stop in Texas holding a sign that read "$5,000 doesn't buy my vote."