WASHINGTON (MarketWatch) – Florida, Florida, Florida.

Those of us who watched election coverage the night of Nov. 7, 2000, can never forget NBC newscaster Tim Russert’s whiteboard with the name of the state, scrawled three times for emphasis, that would determine the victor in the race between Democrat Al Gore and Republican George W. Bush.

Now that the latest polls have put Florida into the “tossup” category and made the race for the White House newly competitive less than 50 days before this year’s vote, the counting of the Electoral College votes has begun in earnest.

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The latest Electoral College map from Real Clear Politics, which tracks and averages state polls, lists 200 votes solid, likely or leaning to Democratic nominee Hillary Clinton, 164 for Republican nominee Donald Trump, and 174 in the tossup category, with 270 needed to win.

Fully 13 states thus become “swing states,” along with a congressional district in Maine — one of two states that splits its Electoral College votes instead of awarding them on a winner-takes-all basis.

RCP’s “no tossups” map — which awards the votes to whoever is currently leading in the polls, even if that lead is within the polls’ margin of error — makes Clinton the winner with 287 votes versus 251 for Trump. Florida, which Trump leads by 0.9% in RCP’s average of state polls, is in the Republican’s column.

This means that Trump, who clearly has the momentum as polls have tightened over the last few weeks, only needs to flip 25 votes to reach that magic number — Pennsylvania (20 votes) and Nevada (6), for instance, or North Carolina (15), Colorado (9) and Nevada.

The Electoral College map at polling website FiveThirtyEight actually awards North Carolina’s 15 votes to Trump, making the race even closer.

Conservative blogger John Hinderaker notes that on the basis of that map the shift of Nevada, New Hampshire (4 votes), and that Maine congressional district (not broken out in FiveThirtyEight), would give Trump the victory with exactly 270 votes.

However, he thinks that Trump will have an easier time of it than that, also winning Michigan (16 votes) and perhaps even Pennsylvania, for a comfortable margin of victory.

Washington Post analyst Chris Cillizza, on the other hand, who has been relentlessly anti-Trump, says “Hillary Clinton remains in the driver’s seat.”

Cillizza considers only four states — Florida, North Carolina, Ohio and Nevada — as real battleground states. Awarding the candidates all the states now leaning toward them, he has Clinton winning 273 to 197. In other words, even if Trump won all four of the battlegrounds, Clinton becomes president, in his view.

Polls still have plenty of time to fluctuate. The first presidential debate next week could prove pivotal, offering Clinton a chance to shift the momentum in her favor and put some of those tossup states back in her column. The Clinton campaign could deploy its considerable resources to counter trends in these key states.

Clinton’s downswing in the wake of her “basket of deplorables” gaffe and her pneumonia-related collapse could prove temporary in any case, giving her a chance to rebound even if the debate is a draw. And of course Trump could go off the rails again, as he did after the Democratic Convention with his stubborn attacks on the Khans, allowing Clinton to open a wide lead.

In any case, polls face a challenging environment to accurately forecast who will show up to vote and how they will cast their ballots as social networking splinters traditional channels of communication.

Particularly this year, respondents may be lying about their choice, given the opprobrium attached to Trump in many circles. Or pollsters may be surveying the wrong people, registering opinions of people who won’t show up to vote and missing those who will.

Nonetheless, if Trump maintains his edge in Florida as well as Ohio, there is no other state, not even Pennsylvania, that is “must-win” for him to have that fabled path to victory.

Politico analyst Stephen Shepard heralded this breakthrough last week in an article headlined “Trump cracks the Electoral College lock.” In six weeks, he noted, Clinton’s lead in Electoral College votes has gone from apparently “insurmountable” to a virtual dead heat.

Come election night on Nov. 8, in short, we may once again be watching an Electoral College standoff as we wait for definitive results from Florida.