Like all candidates, Democrats focus their campaigns on what they will do if elected. Progressives often accuse Joe Biden in particular of wanting to take America back to the Barack Obama years. And it's true that Biden often portrays his candidacy as a restoration of the era in which he served as Obama's vice president.

But that's not a bad stance for any of the Democrats to take. They and their followers must understand that to move forward, America must first move back. The next president must reverse much of the damage President Donald Trump has wrought. The work will be considerable.

We must rejoin our Western allies in honoring international agreements that still make sense. That would include the 2015 nuclear deal with Iran. It reduced sanctions on that country in return for its freezing its nuclear program. Not perfect, but it was working.

After Trump broke the agreement, Iran said it was free to develop nuclear weapons. A nuclear-armed Iran would be a nightmare.

Washington must rejoin civilization's fight against global warming. Trump has almost completed our removal from the Paris climate agreement. Our abandoning it marks a surrender to environmental catastrophe. Some countries are not cutting carbons as they should. America and its conscientious allies can pressure them only if they lead by example.

Trump has shredded regulations curbing the release of planet-warming gases. Some actions were so perverse -- weakening restrictions on methane gas emissions, for example -- that even industries meant to benefit said they didn't want them.

How is it that a beautiful and prosperous nation would consent to being turned into a dump? Among Trump's 95 environmental rollbacks, completed or in progress, was a repeal of the limit on pollution thrown in rivers, lakes, streams and wetlands that are connected to large waterways covered by the Clean Water Act.

He's weakening protections for migratory birds and endangered species. He's opening fabulous landscapes to industry. The most recent outrage was a move to allow drilling and mining on land that was part of Utah's Grand Staircase-Escalante National Monument.

New leadership must reverse the campaign to destroy the Affordable Care Act. Trump has already disabled some of the means for funding the ACA. The law must be strengthened, and then it can be expanded.

The next president must turn off the administration's green light for predatory lenders and their disgraceful abuse of ordinary people. He or she could start by undoing scandalous changes in the student loan system.

Bring back the norms of behavior expected of government leaders. Begin with the easy stuff: Stop bigoted attacks on racial and ethnic minorities. End the blatant self-dealing for personal enrichment. And restore the respect once extended to America's military leaders and diplomats.

Some on the left have criticized the Obama presidency as a lost opportunity to push more progressive goals. Obama should have been tougher on Wall Street, they say, and should have pressed for a stronger government hand in health care.

But Obama was plenty progressive given the awful hand he was dealt. He arrived in the middle of a crashing economy. With the financial system in near collapse, he couldn't risk bringing down what was still standing. The auto industry, meanwhile, was on the edge of bankruptcy. Obama's plate was full. That he managed to push through health reforms, bringing coverage to millions, was no small feat -- doubly so given the Republican opposition that vowed to make him fail.

And so the future must start with an immense repair job. Starting a new Democratic administration where 2016 left off does not leave it in 2016. Once America gets back to some kind of stable normality, we can start moving forward.