Republicans plan to use their first-ever midterm convention in Dallas next month to mount a sweeping, made-for-prime-time case that Democrats have become captive to their activist left, Axios has learned.Why it matters: With President Trump's approval rating in the 30s and his war in Iran weighing on the economy, Republicans don't want the Nov. 3 midterms to be just a referendum on his presidency.They're essentially planning a "But they're worse" campaign targeting the ascendant Democratic left and socialism.Driving the news: Republicans will make progressive politicians and activists recurring characters throughout the Sept. 9-10 convention at the American Airlines Center in Dallas.GOP operatives spent months compiling footage of Democratic figures — including left-wing commentator Hasan Piker and Texas U.S. Senate candidate James Talarico — that they'll use throughout the convention to paint Democrats as outside the mainstream."Our video trove is endless," a convention source told Axios.Organizers will particularly focus on Abdul El-Sayed, the Democratic nominee for Senate in Michigan, who backs Medicare for All and criticizes Israel.Trump has blasted El-Sayed, a Muslim, as a "communist" and a "man of hate" who "hates Israel." (El-Sayed, an epidemiologist, has said he's a capitalist who disagrees with Israel's actions in Gaza, not his "sisters and brothers of the Jewish faith.")Zoom in: Months of polling shaped the GOP convention, organizers say."Everyday Americans" will tout Republican achievements on cutting taxes, lowering prescription drug costs and improving border security — a tactic organizers say worked at the 2024 convention.Organizers believe that will reinforce their argument that Republicans are focused on kitchen-table issues while Democrats have been overtaken by left-wingers whose policies will hurt Americans.The convention will be making that argument at a time when many Republicans have been frustrated by Trump's lack of focus on the economy and affordability issues.Republicans will also spotlight Trump's tax exemption for some tipped income, crime-focused urban policies and the administration's new child investment accounts.Other points of focus will be Vice President Vance's "anti-fraud" task force and Health Secretary Robert F. Kennedy Jr.'s MAHA movement. Trump strategists believe MAHA can again help broaden the GOP coalition.As for the increasingly unpopular war in Iran, the GOP will make the case that Trump has taken steps to protect Americans.Here's what else to expect:Vance will speak the evening of Sept. 9, and Trump on Sept. 10. Trump is expected in the convention hall both nights.Secretary of State Marco Rubio, Treasury Secretary Scott Bessent and some other administration officials will have big speaking roles, as will up-and-coming midterm candidates, UFC figures and celebrities.Unlike in 2024, when donors and delegates filled the floor, the crowd in Dallas will mostly be MAGA activists. The convention will commemorate the first anniversary of the assassination of Charlie Kirk.GOP operatives Justin Caporale and Tony Sayegh are playing major organizational roles, as they did for the 2020 and 2024 conventions.Reality check: The convention will test whether Republicans can move voters toward supporting Trump's domestic agenda, which polls consistently have shown is unpopular.In a CNN poll out last week, 73% thought Trump wasn't paying enough attention to key domestic issues. 65% said his policies were worsening economic conditions.The other side: Democrats decided against holding a midterm convention.DNC spokesperson Kendall Witmer told Axios: "While everyday Americans struggle to pay their bills, fill up their tanks, or put food on the table, Republicans are hosting a multimillion-dollar celebration to satisfy Donald Trump's massive ego and tie vulnerable Republican candidates closer to his failed agenda."