• Single Payer Healthcare. Medicare for all, everyone has coverage. Give up on the pretense of charging people in proportion to risk. Unless we're willing to tell people "no" when they show up bleeding at the emergency room and can't pay, it's foolish to imagine we can limit coverage.
• Build More Housing. A unit is a unit, and when there aren't enough units to go around prices go up and people get forced out. Overall people are leaving high wage states for cheap housing states; they can't afford to stay. To make housing more affordable, make it easier to build.
• Legalize Drugs. Prohibition didn't work for alcohol, and it's not working for pot either. The states that have legalized it are doing well, though we'll know more soon. Probably legalize some other drugs too; probably not the hardest ones.
• Jail People Less. We have way too many people in jail. Drug legalization would help, but we're far too willing to lock people up in general.
• Less Military. Military action is incredibly expensive for what you get. Keep a smaller military, don't go starting wars, and prefer non-military solutions.
• Give People Money. No more EBT, Section 8, Medicaid, student loans, school lunches, or other forms of restricted assistance. No more means testing. No more high marginal tax rates disincentivising work. Give every person rich and poor a minimum income, and charge every person the same income tax percentage from their first dollar earned.
• No Minimum Wage. Once people have a guaranteed income they don't need minimum wages to protect them from exploitation. If someone wants to work and someone else wants to hire them, let them figure out what the rate should be.
• Tax Land Value. Some wealth is mobile and will flee your jurisdiction if you try to tax it, but land isn't going anywhere. Tax the unimproved value of the land, promoting higher value uses of land and letting the taxes fall on the people who can most afford them.
• Tax Harmful Things. Taxes reduce how much people consume, so tax things you want people to consume less of. Generally these are things with externalities: increase the tax until the cost paid includes the full social cost. Carbon taxes are a clear example.
• Reduce Other Taxes. Get rid of sales tax, social security tax, property tax, and everything else you can. Sales taxes are regressive, social security tax only exists for historical political reasons, and land value tax replaces property tax. Keep income tax, maybe raise it, but make it a simple percentage. Guaranteed income progressivizes the taxation.
• Fund Schools Federally. When we fund schools locally our best "public" school districts are really "private," restricted to the children of people rich enough to afford to live in superexpensive areas.
• Let People In. Immigration is good for existing residents, and it's very good for new residents. The potential gains here are very large; stop turning people away.
• Opt-Out Organ Donation. You don't need your organs when you die, but other people do. If you feel strongly about it you should be able to easily opt out, but if you don't care enough to fill out a form saying so then let your organs go on to save lives instead.
• Randomize Everything. Test new policies before rolling them out to everyone. When person-to-person variation works, do that, otherwise pick states at random. For example, you could test single payer healthcare on a random half of people but testing changes to the minimum wage would be harmful if they applied to some people and not others who were direct competitors. This is a check on the policies listed above; I don't know everything, you don't know everything, let's test as we go.

This is an attempt at a balanced list, and I wouldn't necessarily support one policy in isolation.

(What else belongs on this list?)