You may want to note that the Iowa Caucus is important only because it is first; not because it's a flawless bell-weather for the Whitehouse or even the Party nomination.
Examples:
Bill Clinton lost Iowa in 92 (only 3% of the vote) - yet won the nomination.
As did Dukakis in 88.
And George Bush, Sr. in 88.
Mike Huckabee won Iowa in 08 - and lost the nomination.
See the Iowa Caucus is a non-binding, indirect election. The caucus-goers elect delegates to county conventions, who in turn elect delegates to district and state conventions where Iowa's national convention delegates are selected. And it's the Republican Iowa State Convention, not the precinct caucuses, which select the ultimate delegates from Iowa to the Republican National Convention.
Iowa is a big deal really only because pundits and the media make a big deal of it. That's all. How Paul performs in Iowa is close to meaningless. He may lose Iowa, but get the nomination. Or he could win Iowa and lose the nomination.
Predicting things through the Iowa Caucus is like predicting the weather by saying: It was raining this morning....so it will rain every day for the next 3 months.
But to address the threat question. I don't see how it's a threat. What's the media going to do to him...they've already done all they can do.
However, I would vote for Paul if I was sure he'd be assassinated on live tv. That would be cool. I was too young to appreciate Reagan being shot.
Not to mention that he was shot for a dumb reason...and the guy lived.
Lame.