That's because, as Steve Benen noted a couple of years ago, the strategy of total obstruction led them to be "post-policy." Thanks to the work of Michael Grunwald, we all know that strategy was adopted about the time that Barack Obama was inaugurated as President.
So let's take a quick trip down memory lane and think about what was happening at the time. The policies of tax cuts and de-regulation that were embraced by President George Bush had contributed to our economy careening towards another great depression. Osama bin Laden was still alive while our wars in Iraq and Afghanistan seemed both futile and endless. And so, it should come to no surprise to anyone that the country elected a president who promised to take things in a different direction. Republican policies had turned out to be a disaster - both domestically and abroad.
It was at that point that the GOP had some tough choices to make. They could re-examine their policies and priorities based on these results to reframe the conservative alternative politically. Or they could avoid all of that by playing a power game of trying to destruct the liberal alternatives. Of course well all know that they chose the latter.
In order to make that work, they had to fan the flames of anger/fear/racism in their base against President Obama. Hence, the Tea Party was born on lies about death panels, birth certificates and Kenyan socialists.
Now Republicans have a whole slate of presidential candidates who seem eager to run on the threat posed by "Islamic terrorists." But they have no idea about how to do that that doesn't harken back to the disasters created by the Bush administration. So all they've got is to suggest that President Obama's foreign policy is a retreat from our domination on the world stage. How much worse can it get than Sen. Cruz suggesting that it's all about what we call ISIS?
Last week, when Obama requested authorization for the air war in Iraq and Syria, Cruz sidestepped the question of limits and said the main defect of Obama's request was that it failed to identify the adversary as "Islamic terrorists."This is nonsense! And until Republicans can do better than that, no one should take them seriously on foreign policy.