Whether or not an entity can trademark a slogan really depends on how that slogan is to be used. The general principles of trademark law apply in analyzing whether or not the intended or actual use of the slogan constitutes trademark use under the law. At the outset, it is important to understand that a copyright cannot protect a slogan. Therefore, a trademark may be able to do so IF a slogan is used as a source identifier in connection to a particular set of goods or services. Put another way, the slogan must be distinctive, used in interstate commerce, and used as a brand identifier.
To determine whether or not the slogan is distinctive, a trademark attorney can analyze the slogan to ensure that it is not generic or merely descriptive when used in connection with the underlying goods or services. Instead, the slogan must be distinctive, which means that it has either acquired distinctiveness, is arbitrary, or fanciful. Understanding how the slogan will be used will help determine whether or not the slogan is distinctive enough to qualify as a trademark.
The slogan must also be used in interstate commerce as a trademark. Therefore, merely putting it on the front of a t-shirt or some other merely ornamental use does not qualify as a trademark use. It must serve as a source identifier. For example, if used in connection with services, it should be used on a website or other advertising material that confirms that it is a mark. If used in connection with certain goods, such as t-shirts, it must be used on a hang tag, label, or otherwise in such a way that it is clear that it is more than a slogan or phrase without any underlying identification of source for such goods. One looking to protect a slogan would be well served to speak with a trademark attorney who can further advise the proper way to make trademark use of a slogan.
Ultimately, the trademark availability assessment or clearance should be performed on a slogan prior to beginning use or pursuing registration. This will allow a trademark attorney to determine whether or not use of the slogan is likely to subject the entity to claims of trademark infringement, whether or not the slogan is in fact distinctive enough to qualify as a trademark, and provide recommendations as to the likelihood of it being a protectable mark and/or successful trademark registration with the (USPTO) United States Patent and Trademark Office.