Long shot candidate Tulsi Gabbard, the last remaining woman in the Democratic presidential race, is all but certain to be excluded from the party's next presidential debate because of a sharp increase in Democratic National Committee qualifying thresholds.

Candidates will need to earn 20% of all delegates awarded in primary contests before March 15, as calculated by CNN or the Associated Press, to qualify for the March 15 Democratic presidential debate in Arizona, the DNC announced Friday.

With roughly 1,870 delegates up for grabs before the deadline, a candidate must amass about 374 delegates to qualify. Delegate allocation is sometimes delayed as states calculate final results— many delegates from Tuesday's California primary, for instance, have yet to be allocated. In the event some had not been calculated, the DNC will use the number assigned at that time as the total.

[ Opinion: Tulsi Gabbard might have just qualified for the next Democratic debate]

The standard essentially makes it impossible for Gabbard, a Hawaii congresswoman, to qualify for the debate. She earned two delegates from American Samoa's caucus on Super Tuesday, less than 1% of delegates allocated so far. Even if she won every single one of the remaining 358 delegates from primary contests on March 10 and 14, she would be just under the qualifying threshold at 19.3%, assuming all 1,870 delegates were allocated by the deadline.

Former Vice President Joe Biden and Vermont Sen. Bernie Sanders, the last two major candidates in the race, have far surpassed the new threshold.

The last Democratic presidential debate had a much lower threshold. Candidates in South Carolina's Democratic presidential debate had to earn at least one delegate from contests in Iowa, New Hampshire, or Nevada, or reach 10% in at least four DNC-approved national or South Carolina polls or 12% in two early South Carolina polls.

Gabbard's campaign predicted on Wednesday that the DNC would adjust thresholds to keep her from the debate stage.

"While the DNC moved the goal posts by LOWERING them to let billionaire Bloomberg on the stage in February, we can expect them to do the opposite if it means keeping Tulsi off that stage," a fundraising email from the Gabbard campaign said.

Gabbard made headlines at previous Democratic presidential debates by attacking California Sen. Kamala Harris's record on criminal justice and marijuana and for correcting Ohio Rep. Tim Ryan's suggestion that the Taliban, rather than al Qaeda, attacked the United States on 9/11.