President Trump's policy legacy is as much defined by what he's ignored as by what he's involved himself in.The big picture: Over the past four years, Trump has interested himself in only a slim slice of the government he leads. Outside of trade, immigration, a personal war against the "Deep State" and the hot foreign policy issue of the moment, Trump has left many of his Cabinet secretaries to work without interruption, let alone direction. Over lunch in 2017, one of Trump's Cabinet secretaries told me they felt blessed to run an agency that Trump didn't care about. This was the best place to exist, they said.While the media was distracted by the daily drama and treachery of the West Wing, this cabinet secretary gleefully said that they were racing a ton of controversial conservative policy through the system, largely untroubled by pesky journalists.One former Cabinet secretary told me Trump's sole instruction to him, upon taking the job, was "I want you to win." Win what? He had no earthly idea. But he took it to mean he could follow his instincts and assumed he would hear from Trump at some point.As a result of Trump's lack of interest in much of domestic policy, whole swaths of his administration — Education, Housing and Urban Development and Transportation, to name a few — have escaped even the barest presidential attention.Much has been accomplished across many of these agencies, but it's debatable how much of the accomplishments should be described as "Trumpian."That said, here's how Axios' subject matter experts summarize his accomplishments.The economy: Trump made good on his pledges to cut taxes and regulation, which helped create jobs but didn't achieve the levels of economic growth that he had promised, Axios' Dan Primack writes.His trade policies were a mixed bag, improving on NAFTA while flailing on China.In the end, though, Trump's economic legacy was determined by his inability, or unwillingness, to control the pandemic or provide the sort of stimulus that the moment required. Health care: Trump’s failure to contain the coronavirus will also be his most lasting health care legacy. His administration has not accomplished much of its proactive agenda over the past four years, Axios' Sam Baker writes.It started off with a high-profile failure to repeal the Affordable Care Act, and though the administration has chipped away at some parts of the law, most of that could be easily undone — unless the Supreme Court throws the law out altogether.The administration simply did not execute most of its proposals to lower drug prices, and drug pricing has not materially changed.And its efforts to shrink the Medicaid program were blocked in court.Climate: Trump’s legacy on energy and climate change — two inevitably connected issues — are surprisingly opposite of each other, Axios' Amy Harder reports.The oil, natural gas and coal industries are all struggling due to prevailing market conditions despite Trump’s efforts to support them. This is a reminder that despite presidential powers, markets still control commodities.On climate change, Trump’s impact will likely be vast and long-lasting. He has repealed dozens of environmental regulations and infused the U.S. government with a systematic dismissal and scrutiny of mainstream climate-change science.Tech: Trump awakened Republicans' appetite for regulating tech, overseeing a pivot that's likely to outlive his administration, Axios' Kyle Daly reports.He has led the call to revoke a longstanding immunity shield in order to force online platforms to take a lighter hand in enforcing their policies against conservatives.His administration mounted a series of antitrust investigations into Big Tech, with one spawning a Justice Department lawsuit against Google that's likely to usher in a years-spanning court battle.The Trump White House signaled an openness to enacting and enforcing a federal privacy law, but bipartisan congressional efforts to deliver legislation stalled.Artificial intelligence: This is one area in science and technology where Trump can claim some success, Axios' Bryan Walsh reports. Trump called for a doubling of research funding into nondefense AI and quantum computing over the next two years, and earlier this year launched a dozen federal research centers in AI and quantum.Ultimately, though, who wins in the race for AI supremacy will be decided less by the actions of the Trump administration and more by the global firms — many of them U.S. based — that have the will and the resources to push the field forward.   Markets: Trump changed the narrative of the way a president interacts with financial markets, Axios' Dion Rabouin writes.Almost all presidents prefer a weaker dollar because it makes U.S. exports cheaper for foreign buyers and increases U.S.-based companies' foreign profits. But few other presidents in history ever talked about it as explicitly as Trump or called for it.The same is true of the stock market, and the way he badgered and harassed the Federal Reserve when he thought interest rates weren't low enough.Trump's biggest impact on the market and the economy was his choice of Jerome Powell as chairman of the Fed. The impact of Powell's actions to effectively nationalize financial markets will reverberate through the global economy in ways we can't even imagine for decades.Foreign policy: Trump dramatically changed the role America plays in the world and the way the world views America — though Biden has vowed to wipe away "America First" and recommit to U.S. alliances, Axios' Dave Lawler reports.Trump would leave behind normalization deals between Israel and three Arab states, but no nuclear deals with North Korea or Iran.His first term included the failed overthrow of Venezuela's Nicolas Maduro, as well as the killings of Abu Bakr al-Baghdadi and Qasem Soleimani — but no new U.S. military engagements.China: Trump ushered in a new era of direct confrontation with China, a dramatic reversal of decades of previous China policy, Axios' Bethany Allen-Ebrahimian writes.Previous U.S. policy was long based on engagement, the idea that welcoming China into global institutions and trade networks would create a better world for everyone, and might even help China democratize. But the Trump administration shredded that approach. Trump's trade war introduced tough new rhetoric against China and started some U.S. companies down the road of decoupling from their China-based supply chains, and it's not clear if the two-year long trade conflict has benefited the U.S.Science: The Trump administration has prioritized AI, quantum computing, a return to the Moon and the development of new vaccine platforms — all of which may deliver long-term rewards. But the lasting legacy of Trump’s presidency on science is likely to be how he changed the norms around science and politics, Eileen Drage O'Reilly writes.He downplayed the threat of COVID-19 and issued an executive order that critics warn could strip some government scientists of protection from politics, and his appointees tried to censor the work of the CDC.The rhetoric and interference risk eroding public trust in science and its role in creating public policies, just as the country awaits a COVID-19 vaccine and grapples with the devastating impacts of climate change.With the space program, however, Trump put U.S. interests front and center, Axios' Miriam Kramer writes. His administration stood up the Space Force and directed NASA to land people back on the Moon by 2024, a politically motivated deadline that many experts think may be out of reach at this point.