Islamic State stalking democrats in US

National security will not be the defining feature of polls for the House of Representatives and a third of the Senate on November 4.

But, evidence suggests Republican campaign managers believe playing an alarmist national security card could move the needle in tight races in the peak period for advertising expenditures and when many voters are tuning into races for the first time.

A total of 35 percent of those asked in the latest ABC News poll last month said jobs and the economy were the most important factor driving their vote.

By contrast, only 13 percent said international crises would be the defining factor. Arguments over education, immigration and Obama's signature health care law have also raged through the campaign.

But a new bipartisan poll for National Public Radio (NPR) Friday showed national security issues were particularly motivating Republican voters.

Forty-two percent of Republicans said that Islamic State group and foreign policy would influence their vote in November, compared to only 20 percent of Democrats.

Hence, Republicans have a strong incentive to keep banging the foreign policy drum, especially because in mid-term elections, turnout of excited base voters is often determinative and Democrats rarely show the intensity they record in presidential elections.

'Can't let our kids die'

Republican ad men in the decisive states have seized on Obama's previous hesitation over defining a strategy to combat IS and blame his politics for its rise in Iraq and Syria.

"It makes me so mad to see how the president's weakness has allowed the Islamic State to grow," said Nancy Anderson, an army veteran and mother of a Marine, in a new ad released Friday for Thom Tillis in his race against Democratic North Carolina Senator Kay Hagan.

"Senator Hagan, she just goes along with him. We can't let our kids die in vain. We have to change our senator."

For Democrats like Hagan clinging on in states that Republican Mitt Romney won in the 2012 presidential election, a litany of global crises is bad news.

Military-themed arguments have potential potency in North Carolina, where Hagan leads poll averages by four percent, because the state has a large military community.

Republican campaigns were always going to play the military card: In Senate seats which could decide the election -- in New Hampshire, Iowa, Arkansas and Alaska -- their candidates are veterans.

"He served our country in the United States Marine Corps and pursued terrorists across the globe," says an ad for Dan Sullivan, the Republican leading the Alaska Senate race.

Republican Scott Brown, trailing Democratic Senator Jeanne Shaheen in New Hampshire, has an ad showing apocalyptic images of Iraq burning.

In another spot, Brown warns "radical Islamic terrorists are threatening to cause the collapse of our country. President Obama and Senator Shaheen seem confused about the nature of the threat. Not me."

Combat veteran Tom Cotton, up on Democratic Senator Mark Pryor in Arkansas, highlights the turmoil ripping across the globe to tie his opponent to the unpopular president.

"From Russia, tyranny on the advance. A brutal new terrorist threat, determined to destroy America. A world in chaos. And Obama's answer? Weakness," says an narrator above images of global chaos and chilling music.

Presidential flag waving

So what can Obama do?

Officials insist he will not politicize his new campaign of air strikes against the Islamic State group in Syria and Iraq in a manner similar to George W. Bush's hammering of national security themes in 2002 mid-term elections.

The president's approval rating averages in the mid to low 40s and is much worse in the conservative states in which this election will be decided.

That's one reason why few 2014 incumbent Senate candidates want to be seen with the man who helped sweep them to victory at the start of their six-year term with his resounding election win in 2008.

"The single most tangible thing that president Obama can do to help his party in the mid-term elections is to raise money," said Brendan Doherty, professor of political science at the US Naval Academy.

There is some evidence that Obama's ragged approval ratings have improved slightly since he ordered military action after a period of public agonizing and his admission that he didn't "have a strategy yet" to combat IS in Syria.

He is framing a patriotic closing argument, rhetorically wrapping himself in the US flag on foreign policy and the economy.

"One thing should be crystal clear: American leadership is the one constant in an uncertain world," he said Thursday.