My initial thought after the last Republican debate was that it covered - in depth - the United States' greatest concern at the moment: the Islamic State of Iraq and the Levant (ISIL) group.
It's not jobs or the economy, but the fear in the words of New Jersey Governor Chris Christie, that "everywhere in America is a target for these terrorists".
The attacks in Paris, followed by the shootings in San Bernardino, whipped up by frenzied reporting, have left the American people worried about the sweep of global terrorism.
In the early Republican debate (for low-polling candidates) on Wednesday, Senator Lindsey Graham insisted that "[terrorists] are coming here to kill us all. Another 9/11 is coming".
And so in the main debate, almost two and a half hours were dedicated to the threat of ISIL.
It covered how people might be radicalised in the US.
Donald Trump wants to selectively shut down the internet. Rand Paul has proposed bills to limit immigration.
And then there is the threat of ISIL in its Middle East power base.
Here Ted Cruz suggested using the US military's might to carpet bomb the organisation's fighters, perhaps conveniently ignoring that the group is deeply embedded in towns and cities and such a policy could kill hundreds, if not thousands, of innocent people.
Each topic seemed to give the Republicans the opportunity to say how they would do things differently from Barack Obama's White House and, by extension, how they would do things differently from his first Secretary of State, Hillary Clinton, the presumptive Democratic nominee for president.
Yet, observers say the measures proposed in the debate are essentially the same currently employed by the White House.
Slate magazine's Fred Kaplan wrote: "None of these nine candidates had any remotely plausible ideas on how to defeat [ISIL] or prevent terrorist attacks on American soil, beyond what Obama is already doing - except doing it louder, or with a scarier scowl."
What became clear as I thought about the debate, was what was missing from the discussion.
Donald Trump calls for halt on Muslims entering the US
Despite the recent San Bernardino, California, shootings, and this month marking the third anniversary of the Sandy Hook school shooting, there was no discussion of gun control.
Republicans know their base is strong on the second amendment and oppose any gun control measures. The candidates won't touch the subject, even if they want to.
Yet the number of people killed by mass shootings in the US far outweighs the number of Americans killed by terrorism since 9/11.
That is an inconvenient truth.
There was also little mention of climate change, described by senior military commanders in the US as the country's greatest security challenge.
This is even though the global accord to limit carbon emissions was signed just three days before the debate.
John Kasich, the governor of Ohio, criticised the gathering in Paris, suggesting the 195 countries would have been better employed coming up with a plan to defeat ISIL.
That alone shows the dismissive attitude Republicans have towards climate change,and indeed climate science, which some candidates in the past have dismissed.
Do Republicans have a right to be outraged by Trump?
So why were such topics not covered? Why in a debate which lasted more than two and a half hours could these subjects not be broached?
It may be that the discussion and debate on other issues was so lively and engaging that it swallowed up more time. And there is no doubt, the topic of ISIL and the threat in the US is at the heart of many discussions at the moment.
One academic suggested to me there were two reasons for the absence.
One, the host broadcaster, CNN concentrated on the issue which concerns most Americans. Or two, the host broadcaster did not want to upset Republicans and highlight issues which may drive voters away from them.
Remember, one of the questioners was a right-wing radio talk show host, who applauded an answer from Donald Trump.
"What we got," he said, "was a two hour bash Obama fest and that suited the Republicans down to the ground".
It is hard to cover all the ground with nine candidates on stage. There is limited time. But the issues of gun control and climate change are not going away.
The Republican candidates now have more time to fashion their answers.
Source: Al Jazeera