The rest of the country can thank the voters of Iowa for two outcomes of their first-in-the nation caucuses. They have punctured the alleged inevitability of the presidential nominations of Republican Donald Trump and Democrat Hillary Clinton. Each may yet occur, but probably only after a long slog through the remaining state primary and caucus elections.
A clearer picture may come next Tuesday, when New Hampshire voters have their say in the first primary. Mr. Trump will no longer be able to boast that everybody loves him, and Ms. Clinton faces polling showing that Sen. Bernie Sanders of neighboring Vermont holds a very substantial lead.
Similarly significant is the very close third-place finish in Iowa of Florida Sen. Marco Rubio, who with 23.1 percent of the vote was on the heels of Mr. Cruz's 27.7 percent and Mr. Trump's 24.3. Three other centrist Republicans -- Jeb Bush and Govs. Chris Christie of New Jersey and John Kasich of Ohio -- have focused on New Hampshire to challenge Mr. Rubio for the party's establishment label, and they need to put up or shut up there.
Going into the Iowa voting, the dominant political question was whether the bare-knuckle Trump phenomenon would continue to make the 2016 GOP campaign a farce and a vehicle of incivility. Mr. Cruz's own manner, regarded among his Senate peers as comparably sleazy, is not seen as much of an antidote.
In such a close voter outcome, one can only ponder whether many Iowans were turned off by Mr. Trump's petulant row with Fox News and his boycott of that final television debate.
On the Democratic side, Ms. Clinton's miniscule edge over Mr. Sanders in Iowa -- 49.9 percent to 49.6 percent -- was, as the pollsters say, "within the margin of error," enabling Mr. Sanders to claim a virtual victory.
An Iowa cliche is that caucuses offer "three tickets out of the state" and on to the New Hampshire primary, and Messrs. Cruz, Trump and Rubio seized them. Among the Democrats, there turned out to be only two tickets, for Ms. Clinton and Mr. Sanders. The third contender, former Maryland Gov. Martin O'Malley, managed only 0.6 percent and dropped out.
Like Iowa, New Hampshire is lightly populated and traditionally accustomed to retail campaigning -- door-knocking in small towns and villages by the candidates themselves. Mr. Cruz did it to a fare-thee-well in Iowa while Mr. Trump relied more on airport fly-ins aboard his private jet and mass rallies at which he signed autographs along rope-lines while boasting of his greatness in various categories.
It will be interesting to see whether Mr. Trump starts knocking on New Hampshire doors and taking substantive questions from his audiences about some of his more outrageous proposals, rather than just hurling his insults and invectives. Making targets of Mr. Cruz and now Mr. Rubio is likely only to give them larger shares of the campaign spotlight.
As for Hillary Clinton, she barely escaped another jolting setback of the sort she suffered from Barack Obama with her third-place Iowa finish in 2008. Her army of women supporters, determined to break the presidential glass ceiling, managed to stave off the youth crusade for Mr. Sanders but faces it again in the Granite State next week.
As the Democratic campaign moves on to the South Carolina primary thereafter, the Clinton campaign will be relying on a political firewall of other Southern states where Mr. Sanders's self-identification as a democratic socialist may chill conservative voters.
But as the result of the decisions of perhaps only 185,000 Iowans, there is basis for hope that the 2016 campaign has begun to take on a somewhat less carnival atmosphere.
Now also imperiling the Republican Party's once-moderate core is Mr. Cruz, bent on leading its tea party and other ultraconservative elements toward a return to Barry Goldwater-style right-wing purity, and potentially a similar dismal outcome.
The Rubio vote in Iowa represents a glimmer that the old party establishment may find a new savior, now that Jeb Bush has been further humiliated by the 2.8 percent Iowans cast for his forlorn effort.
Jules Witcover is a syndicated columnist and former long-time writer for The Baltimore Sun. His latest book is "The American Vice Presidency: From Irrelevance to Power" (Smithsonian Books). His email is firstname.lastname@example.org.