My guess is that such exaggeration merely reflects what has increasingly been occurring in society at large for quite some time. When it comes to providing information, there is a growing tendency/demand to keep things ever shorter. That context is ideal for exaggeration.
For example, if one examines resumes of prospective employees, one finds a lot of action verbs (consistent with the cookie cutter advice of career services professionals). Quite commonplace is the claim, "I boosted profits by X%." On the surface, that's a concise statement that gets to the point of the value an individual brought.
On closer inspection, it isn't. It is concise, but actually it more often than not clouds over the actual role an individual played in a given firm. It lacks context, some of which can be vital.
Almost always, organizational outcomes are not the result of dictates of a single superhuman who devises the plans, makes the decisions, and implements the measures necessary to reach a given outcome. Therefore, more accurate would be a statement "I contributed to the planning and implementation of a program that led to an X% increase in profits over the past X years."
Unfortunately, even as that statement is much more realistic, it is not as concise as the earlier one. Also, implicit is the idea that others contributed to the effort and share credit for the outcome. In other words, the outcome was not a solo effort. But that's the reality of organizations. Unless one is a sole proprietor, organizational effort is a function of multiple efforts. Team work is pervasive at all levels. But when one is seeking a new position, there is a temptation to avoid sharing credit, even when credit is also due to others.
Potentially even worse from the standpoint of the interviewee is the prospect that he or she might be asked to explain how he or she contributed to the effort, possibly even how he or she worked with others to achieve an outcome. In a "one-minute" world dominated by soundbites, articulating anything to some level of detail can be intimidating for those who are unprepared to do so.
In any case, I don't believe it is suprising at all that larger societal trends have further diluted the political process. The two cases might be among the more notable ones, but on close inspection political literature/claims tends to be skewed toward exaggeration.
