Not if you give it a moment's thought, no. Too much can happen, and many unforeseen or foreseeable things might occur along the way which would affect the contest unimaginably.
Is the American election cycle too long? It is very easy to say yes. Issues and worries such as mentioned above certainly go a long ways towards supporting that answer. Yet we shouldn't be all that sure that the most obvious other democratic system of parliamentary style campaigns are that much better. True, they're shorter. But does that enhance elections or merely condense them to the point where sound bites and knee jerk reactions are all that matter? Given too that they tend to be called when the party in power at least perceives their standing as greater than the opposition and it's easy to wonder if they're a true measure of the will of the people. The parliamentarians may only be manipulating them.
Ideally, longer campaigns should give the voters greater time to consider the candidates and the issues more clearly and thoroughly. Yes, we realize that that's not likely to happen. Indeed, it may never happen at all. Perhaps all we're stuck with with longer election cycles is exactly what we have: an attempted media frenzy over people most of us don't care much about. But we did say ideally.
Still, the vetting process we deal with in these United States does offer something which parliamentary systems don't necessarily. It does allow voters the time to see and hear from candidates they might not get to experience in a more party dominated scheme. And it further allows the crackpots, blowhards, marginal players and egotists a day in the sun before reality, um, sets in. It may also, again, allow the opportunity for a better look at the important issues of the day.
Hey, we're not saying we believe this all true. Yet it does make some sense. At least, more sense than fretting over The Donald's computer prowess.