“The public got more involved earlier this year than in the past, and I think you can point to one person as the reason: Donald Trump,” Mr. Patterson said in an interview.  He added that Mr. Trump has a “water-cooler effect” — people like to talk about him — which could also account for the early voter engagement.  “There’s nothing quite like people talking as an indicator of their engagement in the campaign,” Mr. Patterson said. He added, “Now, whether he gets them thinking is a different thing. But he does get them talking.”  The water-cooler effect is apparent online as well, according to CrowdTangle, a tool that tracks social media usage. The company compared Facebook users’ engagement in the 2012 election between March and September with engagement numbers for the same period of time in 2016. Its findings: the number of public posts that mentioned “Hillary” or “Trump” was roughly the same as the number of posts that mentioned “Obama” or “Romney” in 2012. But the number of interactions — that is, the number of likes, shares and comments generated by users — quadrupled between 2012 and 2016, from 90 million to 361 million. Facebook’s daily active users roughly doubled in that time, but still, that makes it double the users, quadruple the interaction.  “In my opinion, those are pretty amazing numbers,” Brandon Silverman, the co-founder and chief executive of CrowdTangle, said in an email. He added that this election cycle “is generating a massive amount of interest and passion in the election, even this early on, and an extraordinary amount of it is being expressed on Facebook every day.”  Mr. Trump has singularly engaged people in the election — positively or negatively — earlier than voters normally would be paying attention. Last August, more than 24 million viewers tuned in to watch the first debate of the Republican primary, breaking ratings records. By comparison, the most-watched Republican primary debate in 2012 attracted 7.6 million viewers.  Labor Day is also the time when, conventional wisdom says, candidates really start to “pivot” toward the general election, taking a more moderate tack than they did during the primaries. That may be one reason reporters eagerly wondered if Mr. Trump’s visit to Mexico last week, and his subsequent immigration speech in Arizona, represented a potential pivot point. Would he be softening his immigration stance? Would he put a more “humane gloss” on his views toward undocumented immigrants? In the end, no such pivoting, softening, or glossing occurred.  The fact that Mrs. Clinton and Mr. Trump are two of the most polarizing and least well-liked general election candidates in recent history has also likely driven discussion. This election has been more volatile than the last presidential election. Between July and September 2012, President Obama maintained a slim 2-point margin above his Republican challenger, Mitt Romney. Over the same two-month period this year, Mrs. Clinton’s lead over Mr. Trump grew from 5 points to 6.5 points.  So, where does voter fatigue come from, and why does it seem to be getting worse? One part of the problem is that our election season is simply too long. The United States has the longest head-of-state campaign season by a long shot. Senator Ted Cruz, the first serious candidate to announce he was running, announced on March 23, 2015. That means that, by Election Day, the campaign will have gone on for 597 days. In the span with which we’ve been paying attention to the same presidential campaign, we could have instead hosted approximately four Mexican elections, seven Canadian elections, 14 British elections, 14 Australian elections or 41 French elections.  It’s hard not to get exhausted when there’s barely a break between when one campaign ends and speculation about the next campaign begins. Political journalists — ahem — can also claim partial responsibility for voter fatigue. A recent Pew Research Center poll found that roughly six in ten Americans “feel exhausted by the amount of election coverage.” Still, there could be at least one upside to the deluge of campaign coverage over the past year-and-a-half: a large volume of media coverage has been found to contribute to higher voter turnout in November.  That is the irony of this year’s election: Voters are simultaneously more interested in, and more exhausted with, the campaign than in past election years.  So if Labor Day doesn’t really matter anymore, when’s the new starting point for when the election kicks into high gear? Mr. Patterson said the first presidential debate between the two party nominees could act as the new starting gun.  “The conditions are such that the debates could make more of a difference than they normally do,” he said.  While the debates in a “normal” election year mainly serve to solidify both sides’ support for their candidate, this year’s debates could be a potentially huge reckoning for Mr. Trump, who may have gotten off a few zingers during the primary debates, but who has nowhere near the policy fluency that Mrs. Clinton does. That could stand out to voters who haven’t yet made up their minds.  So, undecided voters — yes, all four of you — vacation is over. It’s time for you to start paying attention to every tweet, sound bite and policy proposal that populate your TV, smartphone and computer screen. Come on in, the sludge is fine.
Labor Day is supposed to be the general election starting line. But we got started a long time ago.