The other side of the ledger could be off as well. For example, the $707 billion figure for universal child care factors in economic growth generated by the plan, but under “static” scoring — without assuming any changes in growth — the cost is closer to $1.1 trillion. Similarly, the $470 billion estimate for free college tuition assumes that states would be willing to contribute the remaining one-third that the federal government does not fund.

What Ms. Warren Said

“My 2-cent wealth tax on the top one-tenth of 1 percent of the fortunes in this country, if we use just a piece of that money to forgive student loan debt for about 95 percent of those who have student loan debt, that has huge support among Democrats, independents and Republicans.”

— Fairfax, Va., in May

True.

Several polls have found that Ms. Warren’s wealth tax plan has broad support, though “huge” is a slight overstatement.

Of the respondents, 61 percent supported the proposal in a January survey commissioned by Data for Progress, a left-leaning think tank. More Republicans supported the wealth tax than opposed it, 44 percent to 37 percent, while 61 percent of independents and 76 percent of Democrats also endorsed it.

In a Morning Consult/Politico poll in February, 61 percent of all respondents were in favor of the wealth tax, including 74 percent of Democrats and 50 percent of Republicans.

Polling that month from Survey Monkey for The New York Times produced similar results: 61 percent approval among all respondents, 75 percent among Democrats, 57 percent among independents and 51 percent among Republicans.

An April poll from Quinnipiac University found similar or higher levels of support among all respondents (60 percent), Democrats (82 percent) and independents (63 percent) but notably lower approval from Republicans (32 percent in support and 60 percent in opposition).

Past stance on pot

What Ms. Warren Said

“So, actually, I supported Massachusetts changing its laws on marijuana. Massachusetts had decriminalized at that point and I thought it made a lot more sense for Massachusetts to go ahead and legalize marijuana, and I now support the legalization of marijuana.”

— CNN town-hall-style meeting in April

This is exaggerated.

When a student asked about her evolving position on marijuana legalization, Ms. Warren overstated her past support.