As voters in 11 states flock to the polls, the Vermont senator is looking to shore up his delegate count, which is now at only 70 compared to Hillary Clinton’s 502. To win the nomination, one of them has to amass 2,383 delegates, and Sanders is facing an uphill, but not insurmountable, climb to a win.

The two contenders will be competing for Super Tuesday’s total of 878 delegates (that counts American Samoa and expatriate Democrats voting from overseas), which accounts for about 20% of the overall total number of delegates.

But even as Sanders eyes potential upcoming victories in states like Colorado, Minnesota, Oklahoma, friendly Massachusetts, and his home turf of Vermont, those wins would only place about 300 delegates in his column.

Meanwhile, former Secretary of State Hillary Clinton is expected to win six states on Tuesday: Alabama, Arkansas, Georgia, Tennessee, Texas, and Virginia.

Fortunately for Bernie Sanders, Democratic Party rules require delegates be awarded proportional to the vote tally. It’s not a winner-take-all formula. So the contest continues to be uncertain. Clinton, for example, could pile up some impressive victories and still be a good distance away from locking down the required number of pledged delegates to secure the nomination.

That gives Sanders some room to recover on his way to the July convention in Philadelphia if he can pile up victories in upcoming races in Illinois, Michigan, and Pennsylvania, among others. His record has been mixed to date. He narrowly lost Iowa and Nevada, won a major victory in New Hampshire, and was severely beaten in South Carolina.

Clinton could pull out of Super Tuesday with the wind at her back if she is able to amass enough lopsided victories that garner big delegate awards.

As she battles for delegates, Clinton can’t help but be mindful that in 2008, her opponent Barack Obama turned a small lead in delegates into a juggernaut with a string of strategic victories. This campaign cycle, she has sought to stanch any delegate bleed by hiring advisors that can help target potentially vulnerable areas and make sure that she is not undercut again by the same strategy.

This year, Clinton could marshal another powerful, less than secret weapon – 700 superdelegates, made up of elected Democratic officials and party leaders, many of whom are considered likely to side with her. But using superdelegates to tip the nomination balance would likely ignite a scorched-earth battle between the establishment and anti-establishment forces that each candidate represents.

Then again, such a maneuver would not be at all unusual, according to a book on the presidential primary process written by Elaine C. Kamarck of the Brookings Institution. Since the early 1970s, presidential candidates have tried to alter the nomination rules to their benefit, she said in her 2015 book, Primary Politics: Everything You Need to Know About How America Nominates Its Presidential Candidates.

Even though the battles have been going on for a quarter of a century, she said, “it’s a screwy system” that people forget once it’s over.

“Once the race is over,” she told The Atlantic in February, “people tend to stop asking questions.”