Realistically, a lot of it could just be continuation of existing Biden policy:

• Aggressive antitrust enforcement from the FTC and DOJ, slowly changing the inertia of the last 40 years of allowing consolidation and the neutering of century-old antitrust laws.
• Continued pro-labor rulings from the NLRB to give workers more bargaining power as we unionize at Starbucks, Amazon, and other major workforces. Big union wins at automakers, airlines, logistics companies have emboldened new unionization drives at places like VW provide the momentum that need to be backed by government. Even places where unions have seen setbacks, like Mercedes Benz in Alabama, management has been running scared and trying to stave off unions with promises of unprecedented raises (which they’ve since reneged on after the union vote failed). We need to keep the pressure on, especially as the business cycle potentially turns to a tougher job market.
• Marijuana rescheduling is proceeding along, and hopefully will be complete by the end of Biden’s term. The next administration will need to defend it in court, and implement the details for things like banking and medical research and licensing.

Some Biden policies need to be bolstered with a combination of both continued executive action and new laws passed through Congress:

• Many of Biden’s environmental regulations have been rolled back in the courts. A Harris admin should keep pushing on these fronts, but with coverage from Congress where possible.
• Same with economic/workplace regs. The Department of Labor’s minimum wage exemption guidelines are being challenged in the courts right now, with Biden trying to push for the minimum salary of overtime-exempt workers to be at least $58k next year (the $44k minimum took effect on July 1, 2024). The FTC’s noncompete regulation, which would prohibit noncompete agreements for almost all workers, is tied up in the courts now.
• Biden’s Department of Education has tried to implement student loan forgiveness, and lost at the Supreme Court. Now their watered down measures (easier repayment plans, interest forgiveness for certain borrowers) are in the courts, too. New legislation could fix this.

Abortion, contraception, and family planning in general needs a combination of both strong executive action and new legislation:

• Biden’s administration has fought, with mixed success, to make sure that state bans on abortion don’t interfere with federal priorities. DoD has official policy that pays for servicemembers and their families to travel to states where abortions are legal, if necessary to get care. DOJ and HHS are fighting to make sure that states can’t prevent life saving care that some extremists believe constitute abortion. The FDA has expanded access and availability of abortion medication through telehealth and prescriptions by mail.
• Legislative areas worth fighting for include bolstering the authority of Medicare and FDA to preserve access to abortion and contraceptive care, including across state lines, removing the ban on federal funding for abortions, etc.

These are all pretty modest, but very important. The actual machinery of government is immensely important, and we need people who are effective at making sure everything is working for the people.