I'm not sure of the merits of THIS particular study, but the wholesale rejection of the basic premise is kind of confusing. Does it seem logical that intelligence plays no part in forming political opinions, or that all political ideologies are equally attractive to intelligent people?
However, I will say that it's fairly common in political discussions to hear the word "intellectual" used as a slur, which is probably not a great way to attract intelligent people to your cause.
I think it's fairly safe to say that it's impossible to know or to tell.
However, one could potentially say that, statistically, as the sample size approaches infinity, an "intelligent" person is just as likely to lean left as they are to lean right. Why? Because political ideology is as much a matter of whim as it is rational thought.
Once again, it is not possible to quantify, thus it is not possible to draw any causal relationship between the two. It is entirely arbitrary.
As this study has, and many others have, shown, though, there is a correlation between various groups of people and their ideologies. For instance, college educated people in their early twenties are far more likely to lean left. On the other hand, people who are older or have had to start working earlier (forgoing college educations), tend to lean right. It is, however, nothing more than a correlation. There is no causation.