Editorial: Chaotic driver may hit voter road spikes

US President Donald Trump. Photo / AP

The violence and potential violence of the past few days in America has been shocking - if not surprising.

A Donald Trump-supporting suspect is in custody over bomb threats that targeted Democrat leaders. None of the mail packages detonated. But a former president, secretary of state, vice-president and attorney-general were in the line of fire.

And yesterday, a shooting at a Pittsburgh synagogue killed 11 people.

The US is just 10 days from the Midterm elections. Should the Democrats gain control of the House of Representatives, President Trump will feel the first serious congressional check on his power.

Trump's response to the two incidents has been mixed, even as criticism of his heated rhetoric - and struggle to respond to crises as a president is expected to - has been fierce.

He said of the mail threats: "The bottom line is that Americans must unify ... These terrorising acts are despicable and have no place in our country."

But later he blamed the media, tweeting: "A very big part of the Anger we see today in our society is caused by the purposely false and inaccurate reporting of the Mainstream Media."

On the shooting, Trump tweeted: "This evil Anti-Semitic attack is an assault on humanity. It will take all of us working together to extract the poison of Anti-Semitism from our world. We must unite to conquer hate." But he also said of the synagogue: "If they had some kind of a protection inside the temple, then it could have maybe been a very different situation. They didn't."

Dangerous, disturbed people can be attracted to an angry message - which is why leaders need to be responsible with their language. Former Obama official Colin Kahl tweeted: "When homegrown jihadists commit terrorist attacks, we hold them individually responsible, but we also ask tough questions about the ideologies, rhetoric, & organisations like Isis & al-Qaeda that help radicalise them. We should ask the same questions about right-wing terrorism."

Trump will still light his base to get the best Republican turnout he can. CNN analyst Ron Brownstein tweeted: "Trump's central message to his base is that they are endangered by a constantly evolving array of threats that don't look like them & he is their last line of defence vs. them. Heightening anger/fear is his major fuel."

Presidential approval is a traditional pointer to party fortunes at the Midterms. The RealClearPolitics approval average for Trump yesterday was 44.5 per cent. Democrats lead the RCP average for the generic ballot by 7.6 per cent.

In 2016, Hillary Clinton suffered an "October surprise" with James Comey's intervention 12 days out, reminding voters of her political baggage. Her polling fell from almost a six-point lead. The election was decided by 80,000 votes in three states.

Will these twin outrages hit turnout? Republican leaders denounced the attacks. Yet the electorate has been given examples of cause and effect, and the dangers of a chaotic driver at the wheel.

Keep an eye on the polling.