As poll after poll shows the presidential race tightening, Hillary Clinton has already fired most of her heavy artillery at Donald Trump.

She has called him temperamentally unfit, too dangerous for the Oval Office and ignorant about foreign policy. She has said he makes racist statements and that many of his followers are in fact racist, sexist, xenophobic, homophobic and Islamophobic. She has said he’s built his campaign on prejudice and paranoia. She has denigrated his business record, mocked his corporate bankruptcies and accused him of stiffing small contractors.

What else has she got? How do you stage an October surprise if you’ve gone nuclear in July, August and September?
No wonder Democrats are getting nervous.

After all the stuff dumped on Trump by the Hillary camp and the media, he’s tied in the CBS/New York Times poll, trailing by 1 point in a new Fox News poll, and ahead in such crucial states as Florida and Ohio. So what should Clinton do now?

Rich Lowry made the point quite concisely in Politico:

“The Clinton campaign has already used his greatest hits of most offensive statements in countless TV ads. I was appalled that Trump mocked a disabled reporter, but even I am sick of seeing the clip every other time I turn on the TV. If none of this has sunk Trump and the race gets even closer, what’s left that is going to have a new and different shock value?”

This was always the danger in making the Clinton campaign primarily about demonizing Trump in a change election in which she is undeniably the establishment candidate. He does the same to her, but Trump is identified with a few signature issues: immigration, terrorism and using his business background to create jobs.

Clinton has position papers on everything under the sun, but no single issue that generates excitement and no shorthand to sum up her candidacy. “The other guy’s crazy” isn’t the most inspiring slogan.

One thing that Clinton could do is sell herself as the better choice to the white working-class voters who are defecting to Trump. What will she do to make their lives better? These are folks who are drawn to the Trump brand because they’ve heard so many empty promises over the years and want to shake up Washington.

One thing she’s barely done is to accuse Trump of flip-flopping after having supported Democratic policies in the past—probably because she doesn’t want voters to think he’s actually a closet moderate.

Trump, hardly an orthodox Republican, is trying to make inroads onto Democratic turf—and appeal to women—by proposing paid maternity leave and child-care tax credits. Clinton has her own proposals, but Trump got more attention by using his daughter Ivanka as a TV surrogate. It’s been fascinating to watch conservative pundits say they don’t favor an expansion of the welfare state, then quickly pivot to why this is good politics for Trump.

There’s no question that Clinton, back on the trail yesterday after fighting pneumonia, will continue hammering Trump, in part because that’s what generates headlines. She asked whether America can put a “loose cannon” in charge of the country. But have we reached the point where we’re desensitized to the terrible things these candidates say about each other?

Howard Kurtz is a Fox News analyst and the host of "MediaBuzz" (Sundays 11 a.m. and 5 p.m. ET). He is the author of five books and is based in Washington. Follow him at @HowardKurtz. Click here for more information on Howard Kurtz.