• On Labor Day, at the beginning of September, the decisive phase of the U.S. presidential election campaign begins.

• Democrat Hillary Clinton continues to be favored; however, her lead over Trump in the polls has melted down.

• The campaign might stay dirty to the bitter end – the first TV debate at the end of September is taking on great significance.

The longer an election campaign lasts, the more important the traditions and rituals. Every four years, U.S. candidates trek through the cornfields of Iowa and visit South Carolina’s churches before the favorites stand out on Super Tuesday and the primaries are decided. Interest grows with the conventions – the early summer candidate coronations – but it doesn’t become serious until the beginning of September, after Labor Day.

“Labor Day used to be this big, important marker in the campaign season,” said analyst Amy Walter of the renowned Cook Political Report. “A kickoff, if you will.” Because the holiday is considered the beginning of the actual election campaign, the U.S. media are now filled with interim results. Yet the unpredictable anti-establishment mood (on Labor Day 2015, Trump was considered a laughingstock by most experts) is also leading to a certain languidness and more cautious prognoses. Analyst Walter formulates it like this in The New York Times: “Today, it feels like the start of the third quarter instead of the kickoff.”

The sports analogy explains two different things: The public knows the players, and U.S. citizens have long since formed an opinion of Donald Trump and Hillary Clinton. The real estate mogul has been a permanent presence for 40 years, and the former first lady has been in the limelight just as long. And at the beginning of the second half, the side that is able to force its opponent to take more risks often has the advantage. These are the five most important points in the final sprint of the U.S. presidential campaign:

1. If Clinton loses, it is her own fault. The Democrat continues to lead in the polls (by an average of three percentage points in “Real Clear Politics”), but her eight-point lead is gone. A current CNN survey sees Trump as slightly ahead. It could therefore be even closer than was thought at the beginning of August (more on Nate Silver’s website, “538”).

The basic features of the candidates’ constituents are clear: young voters favor Clinton while Trump is more popular with the older ones. The majority of white voters would vote for the political newcomer Trump (among white college graduates, Clinton gets 49 percent). The historical trend, however, speaks in her favor: Since 1984, the candidate who was ahead on Labor Day got the most votes on Election Day (except for in 2000, when Al Gore lost to George W. Bush); however in this crazy election campaign, much has already been different from before.

2. The first TV debate will be the key moment. When moderator Lester Holt asks Trump and Clinton to take the stage on Sept. 26, many millions in America, as well as in the rest of the world, will be watching. For Trump, who presumably will still be behind in three weeks, everything relies on this: He must show undecided voters that he can represent the United States as president. Even if the expectations are low, this will be a difficult task.

He will only defeat Clinton if he is convincing at the podium – and if he perhaps proves he can work on the details. “Trump has to show that he is acceptable,” judges conservative pollster Neil Newhouse. In principle, Clinton should prevail in the three debates (the last one takes place on Oct. 19). Her problem is more so that she knows too many details and is not understood by normal citizens. Yet, Trump, who is just as unpredictable as he is media-experienced, knows that he needs a special moment. It can go “in a thousand directions,” as political blogger Chris Cillizza enthuses. It certainly will not be boring.

3. It is a matter of organization and mobilization. Because winning the important swing states is necessary in the U.S. electoral system, planning is just as important as organization. Clinton has the advantage here; she is collecting more donations and spending three times as much through her campaign offices. In addition, Obama’s best strategists and data nerds are working for her.

With their help, she has a good chance of getting the necessary votes from blacks, Latinos and young voters, as well as college graduates. To mobilize enough Democrats, she can rely on a progressive “All-Star” team: President Barack Obama, his wife Michelle, and Senators Elizabeth Warren and Bernie Sanders are beating the drums for 68-year-old Clinton. The same is true for her husband, Bill, and daughter, Chelsea, and for virtually all of the Hollywood and pop music stars and starlets. As prominent supporters of Trump, Trump’s grown children (primarily daughter Ivanka), alongside his running mate, Mike Pence, might travel throughout the country.

4. Who would benefit from an “October Surprise”? Until Election Day, a great deal of unforeseeable things can happen. If a particular topic dominates the news for several days, there is talk of an “October Surprise,” in Washington political and media-speak. In 2012, it was primarily Hurricane Sandy that pushed Mitt Romney out of the headlines, while Obama presented himself as a crisis manager at Republican Chris Christie’s side.

Natural catastrophes or a terror attack (domestic or foreign) could influence the mood of U.S. voters just as much as a new revelation from the diverse scandals associated with Trump and Clinton. The Democrats have noted with trepidation the announcement by WikiLeaks founder Julian Assange to publish “a lot more material” from the hacked Democrat emails.

5. Americans don’t like either of the candidates. If the option for “neither of the two” was on the ballot, the conservative Wall Street Journal recently jibed, then Clinton and Trump would have no chance. The newspaper quoted surveys showing that only one out of three of those asked had a positive opinion of the Democrat – for Republican Trump, it was not even one out of four (24 percent). And at the annual meeting of U.S. political scientists in Philadelphia, a participant quipped, “If God had wanted us to vote, he’d have given us better candidates.”

That the 2016 candidates are perceived by many as dishonest (Clinton’s email scandal and family foundation) or quick-tempered (Trump’s fight with the Khan military family) and xenophobic (Trump’s statements about Latinos) has long been known. So insults, attacks and accusations dominate the election campaign. Democrats as well as Republicans are arguing that the candidate on the opposite side will bring the United States to the brink of disaster.

This demonization has far-reaching consequences: It will be difficult for whomever follows Obama in the White House to work together with the representatives of the other party. Because the U.S. political system only seldom allows clear majorities in the Senate and House of Representatives, much speaks for the fact that the maneuvering room of the 45th U.S. president will remain limited.