¶ … unfair" are value judgments -- by definition they cannot be facts. Is it an unfair employment practice for an employer to prefer a U.S. citizen? Any preference not rooted in empirical analysis is unfair -- only hard empirical facts are neutral in that sense. But it is not actually legal to discriminate on the basis of national origin, as per the Civil Rights Act of 1964, Title VII. So such a policy would, for a company that is affected by the law, be illegal. The company is obligated to hire the best candidate who is legally allowed to work in the United States, regardless of their citizenship status. So it's unfair and illegal.

As to whether this is a wise policy or not, it rather depends on one's perspective. Title VII was written as more of a social policy than an employment policy, but of course it directly affects employment. As a matter of eliminating discrimination in the workplace, it's a good policy. But government sets employment policies for other reasons, and since we are discussing foreign workers, the policy is intended to increase and improve the pool of labor available to American corporations. On that score, the policy is effective, because it arguably creates more opportunities for the U.S. To skim top talent away from other countries by giving those high-quality workers more opportunity to get hired in the U.S. If the objective is to improve the prospective immigrant pool, the policy is effective as well. It contrasts with the family focus of other immigration...

easier than people from other countries at face value. Yes, this makes sense, especially in light of NAFTA. Politically, those are the two countries with which the U.S. should have the best relations, as they are our neighbors. Further, more of their best workers can be attracted to the U.S., and the proximity makes them more likely to do it. Economically, there are two ways to look at it. First, with NAFTA there is already relatively smooth movement of goods and capital between the three countries, so it makes sense that labor can also move smoothly. Arguably, NAFTA does not go far enough in this regard, relative to something like the EU. However, the other view is that any preference is going to give rise to economic inefficiency. If the U.S. theoretically set a quota of 500,000 immigrants in a given year, the economically optimal choice is to bring in the 500,000 best. Favoring one country over another serves as a barrier to this, and will create deadweight loss.
Foreign nationals who attend university in the U.S. should have advantages over others. Basically, after four years, those people will have better contacts in the U.S., may have already proven their ability to work, may have received some form of taxpayer financing, and otherwise began to…