No, it's still a bunch of baloney, then as now. America doesn't have the technology or the military budget at the moment to create an impregnable nuclear shield against the delivery devices that exist in the Russian Federation and the PRC. Could we intercept slower rockets from weaker countries, or even indeed those I mentioned? Yep, the tech is all there. But there's plenty that would penetrate the country's airspace and (theoretically) leave even large cities like New York or San Francisco into a pile of ash, to be naturally followed by similar retribution from us.
In other words, what Trump is proposing is not Reagan's hypothetical and never-attempted space shield. He's proposing an actual force that would operate, at least partially, in outer space. The rationale is probably to proactively stop threats rather than hope for an unlikely giant iron dome over the continent to do it instead.
