It’s officially the presidential election year

The early primaries and the Senate trial of Donald Trump could have a big impact

Finally, the presidential campaign has entered the presidential election year.

The turning of the calendar is an important symbolic moment. From here on in, candidates’ political errors that might have been ignored in 2019 will receive rapt attention. From this moment forward, every campaign event will take on fresh urgency. From this day to Feb. 3, the date of the Iowa Caucuses, then on to Feb. 11, the day this state conducts the first presidential primary, the candidates will receive deeper scrutiny, the crowds here and in Iowa will be more discerning, and the candidates will campaign with more fervor.

And one thing more: Though the campaign has stretched for more than a year, for the next six weeks — basically the period in which Canada conducted its entire federal campaign — the impact of the impeachment and perhaps the Senate trial of President Donald Trump will loom large, perhaps affecting the campaigning here, but surely providing hints of the president’s fortunes as he turns to his re-election campaign with new energy.

“The things that matter in this presidential race are going to come on very quickly now that we are in the real election year,’’ said Colin Van Ostern, the Democrats’ unsuccessful gubernatorial nominee in 2016. “A lot will happen and it will all matter. I have seen huge swings in that week between Iowa and New Hampshire, and not always in the same direction.’’

One of the principal reasons for those swings — wholly unanticipated when many of the contenders began their campaigns for the White House — is last month’s impeachment of Mr. Trump and the imminent Senate trial of the president. Already the campaign of Sen. Cory Booker of New Jersey, for example, is working to sculpt a strategy to capitalize on the Senate trial, or at least not to be penalized by the prospect that he and the five other senators running for president will be sidelined in Washington for six days a week during the deliberations.

“All the candidates need to think about appealing to voters while they are off the campaign trail,’’ said James Demers, who headed Barack Obama’s 2008 campaign in New Hampshire and now is a top strategist for Mr. Booker’s effort here. “This could cut either way. Candidates will be locked in Washington. But the Senate trial is going to be a real focus point for voters, so there may be ways to reach them.’’

That is a factor that could affect more than just New Hampshire. Depending on when a Senate trial begins, and depending on how long it lasts, it could lap over to March 3, when 15 states, including delegate-rich California, hold their Super Tuesday contests. Another vital question: How will voters react to an unusual confluence of sentiments? According to the latest Wall Street Journal/NBC News poll: A strong economy plus public fears, by a 56-35% margin, thinks that the country is going in the wrong direction. Unemployment here is at a remarkable 2.6%, a full percentage point lower than the national rate.

Thus the argument that many of the candidates are raising — that the economy may look good on the surface but many Americans are suffering — has less weight here. Even so, the old Democratic trope (‘’Jobs are up because Americans must have two or three jobs to survive’’) still is voiced at candidate meetings and in debates. A 2020 mystery: Will general economic prosperity dilute the prospects of the candidates whose message is essentially economic populism?

Here in the eighth-smallest state one of the other great mysteries is how the 230,000 potential new voters — those not old enough to vote in the 2016 contest plus those who moved into the state in the past four years — might affect this year’s contest.

The majority of both groups, according to a new study by the Carsey School of Public Policy at the University of New Hampshire, are moderates. But fully a third of the young people who have graduated into voter eligibility are likely to lean more liberal.

The implication: This new voter group — plus the notion that about half the potential New Hampshire 2020 electorate could not have voted in 2008 — adds real uncertainty to the primary here, potentially rendering moot long-standing assumptions about voting behavior here. These findings, moreover, suggest that liberal candidates such as Sens. Bernie Sanders of Vermont (the winner four years ago over former Secretary of State Hillary Clinton, the eventual nominee) and Elizabeth Warren of Massachusetts (a state that has produced five winners here in the past six decades) could have hidden power.

“There are more uncertainties in this primary than any I can remember,’’ said former Republican state Rep. David A. Bickford, of New Durham, who has lived in New Hampshire for more than two-thirds of a century. “It’s impossible to guess how things will develop among the Democrats. There are so many candidates, and so many of them are saying the same thing. We still don’t know what will resonate in a rapidly changing state.’’

And yet change has been the great constant here. Once this state boasted the largest textile complex in the world, at Manchester, where 74 cloth-making departments and three dye houses composed an industrial empire (17,000 workers on 8 million square feet of floor space) in a state that still has a rural temperament. Textiles, shoes and wood products no longer are the dominant economic factors. Three of the six biggest employers today: Keene State College, the University of New Hampshire and Dartmouth College.

All this is occurring as small shifts in the tectonics of the 2020 race are occurring. In the fundraising derby — political pros often call money the “first primary’’— there are fresh signs of life for former Vice President Joe Biden and new signs of danger for Ms. Warren, who had been flying high here in her neighbor state until now. The Sanders campaign says it has reached 5 million contributors (an astonishing feat) en route to becoming the champion fundraiser of 2019.

But financial success does not equal political success. For a time in the 1980 presidential campaign, the most prodigious fundraiser was former Treasury Secretary John Connelly. He spent $11 million in hopes of winning the Republican nomination eventually captured by Ronald Reagan. For all that money, Mr. Connelly won a single convention delegate.