Tuesday, Letitia James officially became the new state attorney general. While the race to replace her had already attracted more than two dozen candidates, Wednesday was the true starting gun.

With the sign of a pen, the mayor decreed the special election would take place February 26, starting the clock on a 12-day period during which candidates must gather 3,750 voter signatures to get on the ballot.

"Everything about this race is compressed,” said Dawn Smalls, a former White House aide and first-time candidate.

The signature-gathering process could help thin out the field, which includes nine current or former elected officials. In a show of strength, former City Council Speaker Melissa Mark-Viverito submitted her signatures to the city Board of Elections Thursday morning. By filing first, her name will appear first on the ballot.

Mark-Viverito has another big advantage: campaign cash. As of last summer she had more than $300,000 in a state account, much of it raised during her time in office.

But the fundraising rules for this race are complex. Recently passed City Council legislation allows candidates to take advantage of a new, more generous system of public matching funds: It matches by a ratio of 8-to-1 small contributions up to $250, meaning a $250 donation would yield an additional $2,000 in taxpayer money. Individual contributions would be capped at $1,000.

Or, candidates can choose to raise money under the old rules: a 6-to-1 match on donations up to $175, yielding up to $1,050 in public funds, but with a higher contribution limit of $2,550. In either case, to qualify for matching funds, candidates must raise $62,500 in small donations.

Between now and February 26, current City Council Speaker Corey Johnson will take on the role of acting public advocate, and has promised an aggressive approach to the role.