Mollie Hemingway of the Federalist documents several ways in which national Democrats appear to exhibit fear about Donald Trump’s presidential challenge.

(1) They Changed Hillary’s Tagline

In his acceptance speech at the Republican convention, Donald Trump said,

My opponent asks her supporters to recite a three-word loyalty pledge. It reads: ‘I’m With Her.’ I choose to recite a different pledge. My pledge reads: ‘I’m with you — the American people.’

He went on to describe the ways he would be with voters. It was a really smart line that made Clinton’s tagline seem cold and entitled, out for herself. It made Trump seem like he was for the common man. “I’m with her” was used to great effect during the campaign. But all of a sudden the line conjured up negative feelings.

The Clinton campaign responded by changing her slogan. Or not changing it so much as adding to it. Now, on the backside of signs that say, “I’m with her,” there’s an additional tagline: “She’s with us.” …

… (2) Their Mockery of Trump Is Obsessive

There are advantages to being the second party to hold a convention. You get to react to the first convention by presenting a more appealing message. You get to react to things you thought were negative.

But at no time should you build an entire joke around something as narrow as the way your opponent walked onstage. …

… (3) Policy Changes

Here’s yesterday’s lede from the Detroit Free Press:

PHILADELPHIA — UAW President Dennis Williams reiterated Tuesday that presumptive Democratic nominee Hillary Clinton has promised him that she will try to rewrite the North American Free Trade Agreement (NAFTA) to better protect workers.

Promised him she’d rewrite one of her husband’s signature policy achievements. …

… That could be seen as nothing more than an attempt to tamp down the Bernie Sanders troops, but Politico Pro reported that Clinton surrogate Ed Rendell is crediting Trump’s attacks on trade agreements. He says Trump’s trade message is resonating in the important swing state of Pennsylvania. …

… (4) The Change-Maker?

During his acceptance speech, Donald Trump sold a message of the need for radical and urgent change.

Big business, elite media and major donors are lining up behind the campaign of my opponent because they know she will keep our rigged system in place.

They are throwing money at her because they have total control over everything she does. She is their puppet, and they pull the strings.

That is why Hillary Clinton’s message is that things will never change. My message is that things have to change — and they have to change right now.

So what was the big takeaway from [the] keynote address by former President Bill Clinton? He said that his wife would be a “change-maker.” Over and over and over again, that’s what he said.