That does not have to involve any prospective gains, but be merely a "garbage can" behavior well documented in organizational theory. According to the "garbage can" model, organizational actors tend to adopt options that in the past proved to be the least problematic to- and easiest to accept by- all stakeholders, which then they rationalize as "profit maximization." Stated differently, they opt for transaction-cost minimizing rather than utility maximizing.
The nonsensical US policy toward Cuba is a good example. This policy makes no economic sense whatsoever, and it actually hurts US business interests (e.g. agriculture) which would profit from trading with Cuba. However, any administration attempting to change this policy would immediately be targeted by the opposition to score a few easy points by making a "soft on communism" charge. Therefore, any potential economic gain from normalizing relationship with Cuba is not large enough to outweigh the political risk of a policy change.
The bottom line is that idiotic foreign policies can offer some immediate political gain at home at minimal cost - or rather that the cost is borne by those who do not live in the US and do not "count." The loss of material gain these policies produce is a small price to pay for achieving internal goals of the US administration.
Wojtek