With gas above $4.50 a gallon and inflation running at 3.8%, Democrats think they’ve found their midterm weapon: Donald Trump’s gold-plated White House.

Senate Democrats have dubbed their GOP colleagues “Ballroom Republicans,” hoping the nickname sticks through November as voters sour on the president’s federal beautification push — a portfolio that includes a $400 million East Wing ballroom, a $250 million triumphal arch near the Lincoln Memorial, a $40 million sculpture garden and a $13 million reflecting pool overhaul.

“The American people now spend well over $32 billion more on gas and diesel since the beginning of this war, and this president is just continuing to put gold up all over the White House,” said Sen. Andy Kim, New Jersey Democrat. “The people back home said a line that really struck me. They said, ’What about us?’”

A Washington Post-ABC News-Ipsos poll found 56% of voters oppose the ballroom project. A majority also opposes the arch.

Mr. Trump has called the ballroom “a gift to the United States of America,” noting it is privately funded. But he is also seeking $1 billion in federal security funds partly tied to the new construction — a request that has Republicans in Congress quietly squirming ahead of midterms.

“We are in a political season,” Senate Republican leader John Thune acknowledged.

Democrats smell opportunity.

“Republicans are fighting like hell to waste billions of dollars on things taxpayers do not want,” said Senate Democratic leader Charles E. Schumer of New York.

Read more:

• Ballroom backlash: Trump’s gilded projects become flashpoint ahead of midterm elections