But disgruntled Quinn supporters have faulted her for not drawing more attention to the history-making nature of her candidacy. Quinn, once the front-runner, now desperately needs her West Side base to show up if she has any hope of making a runoff.
There are hints her support could be fracturing under the weight of her complicated relationship with Bloomberg in the city council, and de Blasio's late burst of momentum.
When de Blasio showed up late last week to campaign in Quinn's backyard, on the corner of 23rd Street and Eighth Avenue, he was mobbed by photo-seeking supporters and held court for nearly an hour, jamming up foot traffic and putting the City Council speaker on notice. On Monday night, Quinn's campaign added a last-minute campaign swing through Chelsea to shore up her base.
4. Can Spitzer make a comeback?
Spitzer, who resigned from office in a 2008 prostitution scandal that roiled Albany, surprised pretty much everyone in politics in July when he suddenly jumped into the Democratic race for city comptroller, the city's chief fiscal officer.
With the help of his real estate fortune, his unabashed anti-Wall Street rhetoric and his near universal name recognition, Spitzer led his Democratic primary opponent, Manhattan Borough President Scott Stringer, for most of the summer.
But Stringer has worked overtime to remind voters of Spitzer's baggage, attacking him in debates, in the mail and on the television airwaves. Spitzer has returned fire, accusing Stringer of being a lifelong member of the political establishment who accomplished little during his public career. The race is the most intriguing head-to-head match-up on Tuesday.
Recent polls paint a mixed picture but suggest the race is something of a toss-up, though Spitzer may have a slight edge thanks to his steady 2-1 edge among African-American voters. If he wins the nomination, he's a sure bet to become comptroller against nominal Republican opposition and see his name bandied about as a potential future mayor, attorney general or governor. A win Tuesday would be his first step toward political redemption.
5. The end of "Cats"
The Republican primary contest has been largely overlooked given the city's Democratic leanings. Roughly 700,000 Democrats are expected to cast ballots in Tuesday's primary, while Republican turnout may be as low as 60,000.
Joe Lhota, a fedora-wearing veteran of Rudy Giuliani's administration, is expected to win the GOP nod. If the liberal de Blasio wins the Democratic primary as expected, Lhota might have an outside shot in the general election if he's able to enlist Bloomberg allies and the business community, no fans of de Blasio's tax-the-rich agenda, to help defeat him.
But a Lhota win would also be the political death knell for John Catsimatidis, arguably the most colorful figure of the 2013 election cycle. Catsimatidis, the Greek-born billionaire founder of the Gristedes grocery store chain and a longtime Republican donor, poured millions of dollars of his own money into the race, blanketing the television airwaves with quirky television ads.
According to The New York Times, "He has even created his own eight-page newspaper, The Cats Chronicle, which includes no fewer than 27 photographs of Mr. Catsimatidis."
Politically incorrect, often disheveled and definitely overweight, Catsimatidis has some regular guy appeal but is nevertheless prone to missteps and cringe-worthy statements that make him hard to take seriously. He even fell asleep in the middle of an interview with a New York public radio reporter, who recorded him snoring and used the sound in her story.
Russell Schaffer, a New York Democrat who tweets prolifically under the handle @RussOnPolitics, spoke for political junkies everywhere on Sunday when he mourned Catsimatidis' imminent demise:
"I'll never let @JCats2013 go, even after he loses the GOP primary for NYC mayor on Tuesday," he tweeted. "He is a treasure to behold and quote."