I'm not smart, but the first thing would be to pull whatever lever in the war powers act reigns in the president and stop the fucking Iran war. Next impeach motherfuckers. Depending on how much of a majority, look at passing laws that are veto-proof and actually do things like cap student loan payments, add back the SNAP funding, and maybe actually force the EPA/FDA/FCC/other captured agencies to not tear down their own organizations. But I'm sure the best we'll get is a strongly worded letter from Schumer.