... Republicans were searching for an enemy with which they could distract the American people from their redistribution of wealth from the middle class to the rich. So far they have found that enemy in Islamic fundamentalism - but that enemy may not serve the purpose in the long term.
Communism's threat was the creation of a competing system which challenged the Republican world view. But, despite its talk about a caliphate, jihadism has shown no capability or interest in creating any kind of social construct. All it does is destroy. So it will be, in the long term, insignificant, fading away as do all movements which have nothing positive to offer.
What will the Republicans replace it with? The greatest threat to America now is posed by China, and China is a real threat to the Republicans. The corporations which have abetted China's rise have probably destroyed the future of the Republican party - because it's unlikely in the Chinese century that it will be as easy for Americans as it has been to create great wealth, and those few Americans who do create it will be functioning globally and will not need to dominate the American political system, or even use it. There will be no need for the party.
That may put the politicians out of work, since the Republican base will not be able to rejuvenate itself. But by the time China becomes self-sufficient to the point that it doesn't need to make Americans rich, the current Republican base - the now rich, not the "values goobers" - will have accumulated their pile and can leave the sinking American ship and live wherever they like.
So take comfort, folks - when America goes third-world, there will be no more Republicans. And if by some chance the values goobers keep the party alive, they won't need to find an enemy to replace the jihadists. By then, Americans will know that our enemy is us.