The thing is that many people are looking too short-sightedly for the internal (non-revolution-like) reform path. The goal for change is 2028, but change in 2028 can't get off the ground running, if a 2026 sweep doesn't. (I wish you had a Westminster system with no-confidence votes, but alas).
What Congress can do is to compel Trump administration officials to get their asses into the chamber. They can put articles and lawsuits with appropriate standing to:
- Halt ballroom construction.
- Halt reckless and unnecessary tariffs.
- Halt the endless war spending on the unauthorized military adventure Iran.
- Halt funding for Israel.
- Abolish/stymie/revoke funding from ICE.
- Have the DoJ release the Epstein files.
- Assess Trump's mental state and capacity to lead.
- Release funding that Congress allocated but the Trump admin is withholding or disbursing unevenly (e.g. FEMA)
- Collect evidence to make the case to impeach the justices or reform the Supreme Court in 2028.
Congress under leadership of feckless Republicans and sometimes Democrats haven't asserted the power of the purse. For budgetary matters, votes can be held removing the cloture rule. And if Trump refuses to sign a bill voted on D-party lines to fund the government while implementing changes, the government will shut down once again and the bill will await him on the desk until he signs it. He will try to shift blame as he always does, but the government has shutdown led by Republicans or Democrats, the common thread is his incompetent ass in charge for most of the time since 2016.