Some candidates, most specifically Joe Biden , have entered the race to restore the country to the pre-Trump era of President Barack Obama. On the other side is a group of Democrats and independent Bernie Sanders who are offering more radical transformation.

They are pushing very specific proposals for big, expensive ideas and want the federal government providing more direct help to each citizen.

Every Democrat wants to address climate change, gun control and the nation's crumbling infrastructure. But there's less agreement on how to deal with racial disparity and inequality, whether to force Americans into a government-run health care system and whether or how to rebuild elements of the US system of government.

Here's a look at some of the more novel and transformational proposals that Democratic candidates are pushing. This is not a survey of where all Democrats agree, so we've left out the Green New Deal, which many support but which lacks many specifics.

You'll notice that some candidates -- Sens. Sanders of Vermont, Elizabeth Warren of Massachusetts and Cory Booker of New Jersey -- have more entries than others. And that some candidates who don't get a lot of mainstream media attention or have a following in the polls, like John Delaney and Andrew Yang, have fully formed and interesting proposals. Meanwhile, some candidates who get a lot of attention have fewer specific and no revolutionary proposals.

We've tried to focus on the first candidate in the race to suggest something this year. Others have since agreed with many of these ideas.

Address inequality; expand the safety net

Addressing inequality is something every Democratic candidate would support. But few have a concrete way to do it. Some of these proposals do double duty, having been suggested as remedies to racial inequality, which we'll explore further down.

One of the most specific and intriguing ideas comes from Booker, who wants to give every American child a nest egg. Kids who come from less would get larger nest eggs for college or down payments. But every child would get something. Booker says giving kids a nest egg that matures when they're 18 would help people on the lower rungs of society create wealth . It would address racial and income inequality and the cost of tuition in one program.

Most of the Democratic candidates say they support universal health care, but that's a phrase that would take many forms. Sanders has led the way with his "Medicare for All" proposal , which would replace the US system with one run by the government, similar to the Medicare now enjoyed by senior citizens. Whether the current market system could or should be replaced, however, has led to some disagreement among Democrats and some offshoot proposals for Medicare buy-in. A number of fellow candidates have endorsed Sanders' plan along with the less radical buy-in proposal.

Former Rep. Delaney of Maryland has his own proposal , which would replace the current system with a hybrid: The government would cover basic health care services, and market plans could be bought for additional coverage.

Most candidates are talking about the need to reduce higher education costs and to address what many people call a crisis of student loan debt in the country. Sanders has led the way here too, but the most ambitious plan was recently announced by Warren, who would forgive most student debt held by the government and raise taxes on the wealthy to make tuition at public schools free.

Raise taxes

To deliver these programs, capital will need to be raised, and there are two serious proposals to ask Americans who have the most to bear the burden.

Sanders and Warren also have the most specific plans on how to raise revenue to pay for their plans. Both would target the richest Americans with new taxes on their wealth. Warren's proposal for a tax on assets would be an important step further than the current US tax code, which is focused on income. Republicans scaled back the estate tax when they passed their tax cut law in 2017, but Sanders would bring it back in an even bigger way. These ideas aren't crazy. Before he was a Republican, even Donald Trump had a specific proposal to tax wealth back in 1999 , although he wanted to use the money to pay down the national debt.

Put Americans to work

Unemployment is near historic lows, but not everyone has the job they want. People decide which job to take or how much to work and how to live their lives based on many factors. These proposals could alleviate some of the pressures that drive workers toward certain roles.

In pitching her plan for universal child care paid for largely by the government, Warren doesn't focus on children but on working parents. The cost of child care, she says in a Medium post , is a barrier to Americans staying in the work force. She'd pay for this new benefit with her tax on wealth.

Yang doesn't say he'll give every American a job, but he does want to give everyone an income -- $1,000 per month, regardless of what they make at their day jobs. Giving money to the wealthy would frustrate some, but Yang says it would be fair to give to everyone and it would help most among low-income Americans who live paycheck to paycheck. Booker's proposal to study a federal jobs guarantee is more of a half measure, but it has support among other people running for president.

Delaney and Yang are raising alarms about the rise of automated labor, featuring it prominently on both of their websites. It is not an issue other candidates are talking about.

Challenge the US system

Among the boldest -- and most difficult to enact -- proposals are the ones that challenge the entire US system of government and seek to right historical wrongs, change long-standing customs or completely alter US foreign policy.

The idea of reparations for the descendants of slaves has emerged as a divisive issue for Democrats this year. Williamson is out front with a specific proposal to dedicate hundreds of billions of dollars in direct payments to African Americans. Others in the field, like Booker and Sen. Kamala Harris of California, want to study the idea. They've also pitched proposals aimed at low-income Americans, like Booker's baby bonds, as a salve for racial inequality since they could disproportionately help African Americans.

Democrats have been grousing about the Electoral College for decades and the idea to get rid of it has been endorsed before, as Hillary Clinton did after she won the popular vote but lost the presidency in 2016. Two Democrats in the past 20 years have suffered that fate, compared with zero Republicans.

Warren was the first Democrat to bring it up this year. That's because the Electoral College gives more power to individual voters from smaller states, many of which happen to support Republicans. This isn't happening anytime soon, but it does speak to Democrats' general frustration that the peculiarities of a 200-plus-year-old system seem to help the other side and hurt them. Ditto the endorsement by Warren, and to a lesser extent by other Democrats, to end the filibuster in the Senate . That doesn't take a constitutional amendment and the Republicans who control the Senate seem ultimately headed in that direction anyway.

They're also smarting after Trump, with an assist by Senate Majority Leader Mitch McConnell's obstruction of Obama, was able to get two Supreme Court justices appointed in two years. They're unelected and they're on the bench for life. It doesn't take a constitutional amendment to change the court, and its makeup has been revised multiple times in the past. South Bend, Indiana, Mayor Buttigieg doesn't have specific proposals on much, but he has teased an idea to make the court bigger and give both Republicans and Democrats a say in filling the seats

Trump worked with Democrats like Booker to pass the First Step Act, the most extensive overhaul of prison and sentencing laws in years, and he's argued that the bipartisan measure is a key part of his legacy. Booker would go much further with sentencing and he's proposed a bill that would substantially change the guidelines.

Sanders doesn't have a specific proposal to let convicted felons vote while in prison, but he was asked at a CNN town hall if he supported the idea of a terrorist like the Boston Marathon bomber voting from behind bars. He said yes. Felons can vote while in prison in Vermont. And some states have moved to restore voting rights to felons after they're released. States control voting rights, so a President Sanders wouldn't be able to enact this, but it was an interesting moment and could turn into a divisive idea.

Gabbard is an Army and Iraq War veteran. The congresswoman from Hawaii has drawn criticism for meeting with Syrian leader Bashar al-Assad. But she has firsthand knowledge of what US regime change looks like and she doesn't agree with it , although foreign policy and non-interventionism do not have the same place in the American political conversation now that they did during the Iraq War.

Control capitalism

Not all of the proposals have to do with addressing inequality from the bottom up. There are also ideas for how to hem in the corporations and banks that have grown the largest.

big companies Warren is beyond most of the field with her proposal to break upbigcompanies like Amazon and Facebook . Her proposal aims to make the platforms they control fairer for other businesses to access.