In short, the answer to this question is no. According to dictionary.com theocracy is defined as:
the·oc·ra·cy [thee-ok-ruh-see] Show IPA
noun, plural the·oc·ra·cies.
1. a form of government in which God or a deity is recognized as the
supreme civil ruler, the God's or deity's laws being interpreted by the
2. a system of government by priests claiming a divine commission.
3. a commonwealth or state under such a form or system of government.
[see this page]
Taken literally or strictly, theocracy means rule by God or gods and
refers primarily to an internal "rule of the heart", especially in its biblical
application. The common, generic use of the term, as defined above in
terms of rule by a church or analogous religious leadership, would be
more accurately described as an ecclesiocracy. [link added]
Wikipedia also notes that "[h]aving a state religion is not sufficient to be a theocracy. Many countries have a state religion without the government directly deriving its powers from a divine authority or a religious authority directly exercising governmental powers." (see this subsection)
Basically, in order for a government to be a theocracy, the government must claim that it receives its powers directly from God and the rulers are also the head of the church. The United States in no way, shape, or form falls within this definition. I will not deny that many leaders in government are influenced by their religious beliefs or mention God frequently [particularly (but not exclusively) in the right wing of the Republican party], however this is not enough to classify the US as a theocracy regardless of what atheists or secularists would have you believe.
A part of the problem is that the word, like many words, is being misused by people on an epic scale. People are trying to make the word "theocracy" mean that any influence on government by religion makes a government theocratic. What they fail to appreciate (or completely and purposefully ignore) is the idea that people's personal and religious beliefs are going to affect how they govern. This is natural and not some vast conspiracy aimed at making everyone follow a particular religion. I will not deny that there are people who allow their religious beliefs to influence them in inappropriate ways (see this story), but these instances are not some scheme to force people to become Christians anymore than issues like universal health care or reasonable gun control are a part of some massive conspiracy to strip people of their rights.
This issue is a part of a larger problem that I have talked about before. People today are having a much easier time finding a group of like-minded people and blockading themselves within these groups. This tendency has always been around, but we now have an easier time doing it because of the internet and social media giving more and more people a platform from which they can pontificate and make assertions that may or may not be groundless. When people form these little groups, they fall prey to groupthink and self-reinforcing thoughts where any incident can be fit into an overly simplistic paradigm or worldview and any incidents which do not fit in the same can be ignored or misconstrued. People no longer take the time to think about things before they react. Rather, they put their first thoughts out into the world and these thoughts are often based on incomplete or incorrect information or (even worse) are based on pure emotionalism with no evidence of rational thought.
I will admit that I too fall prey to this sometimes, which is why I will often try and take time to think about something for a few days prior to writing or reacting to it. The tendency mentioned above is exacerbated by, and contributes to, the increasing political polarization that I have written about before. For some related blog posts go here and here.
So those are my thoughts. Any other thoughts?