Sen. Elizabeth Warren, seeking to sustain her momentum in the Democratic presidential race, is proposing an across-the-board increase in Social Security benefits, financed by new taxes on high-income Americans.

Rolling out the plan Thursday morning, hours before the third presidential debate, Warren called for an immediate benefit increase of $200 per month for current and future beneficiaries. At the same time, the Massachusetts Democrat proposed new rules that would provide additional benefit increases for low-income, female, disabled, minority, and former government worker beneficiaries, reasoning that they've been shortchanged by the existing structure of the program.

To pay for it, Warren would impose new taxes on what she calls the richest 2% of Americans. She would eliminate the income cap on Social Security taxes for those earning more than $250,000 a year, imposing a 14.8% levy on incomes above that amount, split evenly between employers and employees.

In addition, she is calling for another 14.8% levy on investment income for individuals earning more than $250,000 and couples earning more than $400,000. Taken together, according to an analysis Warren released from Moody's economist Mark Zandi, those taxes would not only pay for the new benefits but provide enough additional revenue to extend Social Security's solvency by 19 years beyond current projections.