Extremists on the right make threats about the dangerous "other" who might take the White House. Hotheads on the left rant that they won't be happy just beating the Republicans; they want to destroy conservatism itself.
All the more reason, in these unsettling days, to celebrate a few cool heads: political commentators who have been wise enough to look beyond the frantic partisanship of the moment to ponder how the country might be governed when the shouting is over.
In an extraordinary conversation on CNN last week, two old White House hands made a reassuring stand for reason, calling on John McCain, in particular, to start thinking about how history will judge him.
A glum Ed Rollins, who helped elect Ronald Reagan and then served him in the White House, told host Anderson Cooper on Thursday that he believed McCain's prospects of winning the presidency had vanished. The late-campaign attacks on Barack Obama would be for naught.
"Barack has met the threshold where people think he's going to be a leader," Rollins said. "He's tied McCain to the past and [President] Bush, and I think people clearly want to make a move."
Rollins' tone and grim face made clear that he took no pleasure in this conclusion. He said he would still vote for McCain. But his outlook and his status as a Republican elder gave his next statement considerable weight:
"The other fundamental question here is 'How do you want to end your career?,' if John McCain ends his career."
Rollins suggested McCain should spend the final weeks of the campaign leading his party away from the red-meat attacks on Obama that dominated last week, even if that's what some GOP true believers craved.
"You have to go give an alternative on the economy," Rollins said. "He has got to be prepared this week to go out and really have a good, strong talk about economic leadership, so that his party has a little bit of something to run on."
To do otherwise could give the Democrats not only the White House but sweeping congressional victories and a potentially filibuster-proof super-majority in the Senate, Rollins suggested.
David Gergen, a White House advisor to three Republicans and a Democrat, Bill Clinton, sat beside Rollins and mostly agreed. He said he was less convinced that McCain was finished but that he worried about the "free-floating . . . anger that could really lead to some violence. I think we're not far from that."
"But I think McCain ought to get his campaign off the road," Gergen added, "and . . . get the best economic minds in the country together and come back Monday, Tuesday, with a really serious speech."
It's unclear whether McCain and running mate Sarah Palin heard those words. But something caused them to dial back their attacks on Obama as they campaigned Friday.
I haven't yet seen commentators making a similar call on Obama, to refocus on the future. But it's time.
He could continue to depict McCain as unstable and intransigent. He probably won't pay much of an electoral penalty, and he might even win a few more votes. But it won't help him bridge the partisan divide in Washington, something he says will be necessary to solve the most daunting challenges we have faced in generations.
One of the most articulate and persuasive critics of excess partisanship has been journalist Ronald Brownstein. Brownstein wrote powerfully in the Atlantic magazine last month about the forces that would tend to drive McCain and Obama into the ideological edges, rather than the broad middle where they would have more chance to advance real change.
"Months of this sniping tend to harden the country's divisions and diminish the eventual winner's ability to govern," wrote Brownstein, a former Los Angeles Times reporter. "Any goodwill that either nominee evokes among the supporters of the other at the start of the campaign is now reliably extinguished by the end."
He challenged Obama to break from his tendency to hew to the Democratic Party line. He hoped that the more ideological McCain would recede in favor of the McCain who forged compromises on campaign finance reform, judicial appointments and immigration.
Brownstein knows as much about the political verities of the moment as any commentator out there. But he also has the wisdom to look both into our past and into the future to make a simple case -- that "presidents who divide rarely conquer."