Warren made nearly $2 million from legal work

U.S. Democratic candidate Elizabeth Warren on Sunday (December 8) revealed nearly $2 million dollars in compensation for legal work going back to 1985.

Warren's campaign put out the information following pressure from rival Pete Buttigieg

Fighting Wall Street greed has been a major theme of Warren's populist campaign.

That may have opened her up to criticism that she herself has profited from the corporate world.

She's already released 10 years of tax returns

But recently, Buttigieg called on her to go back further - and release more information.

Warren hasn't taken it sitting down

She's demanded, in her turn, that Buttigieg share more details about his own past work at consulting giant McKinsey.

On Sunday (December 8), Buttigieg's campaign said he's working on that.

An opinion poll last week showed Warren's support is slumping nationally.

She's come under attack for her plan to extend government-paid healthcare to all Americans - a plan that some candidates call too expensive.

In some states, the 70 year old is still running near the front of a pack of 15 Democrats.

That includes Iowa , which kicks off the party's nominating contests early next year.

But she'll have a tough challenger in Buttigieg.

Recent opinion polls in Iowa show the mayor from South Bend, Indiana has surged into the lead there.

The two will have a chance to tussle over the issue of transparency in person when they meet on the debate stage in Los Angeles later this month.