In 1492, Columbus sailed the ocean blue. In order for him to sail the ocean blue, he had to get funding from King Ferdinand and Queen Isabella. He got permission to travel in January and left on August 3.
What happened between those two points? The Alhambra Decree, issued on March 31, which formally expelled Jews from Spain. They either had to convert to Christianity or, in modern parlance, GTFO. Spain was not the first country in Europe to do so, nor were they the last. Jews who left were not permitted to take gold or silver with them, and anyone found to be hiding a Jew had all their property confiscated. Rumors went around that some Jews had swallowed gold and jewelry in order to smuggle it out, and as a result they tended to get shanked mid-flee so as to get at the gold. (The ones who converted ended up getting persecuted anyway.)
The Columbus money didn't quite come from them, but it did come from a couple Jewish financiers who freely coughed up the cash: Louis de Santangel, Gabriel Sanchez and rabbi Don Isaac Abrabanel. Columbus set sail the day after the deadline came for Jews to get out of Spain or be executed.
Meanwhile, in 2014, a proposal is on the table in the Spanish legislature to reinstate that citizenship. The Alhambra Decree was formally revoked in 1968, in one of those instances where someone has long since stopped doing a terrible thing but doesn't get around to doing the paperwork until a long time afterwards. This is just going further down that road. Citizenship would be extended to any descendant of the expelled Jews, known as Sephardic Jews, whether they actually live in Spain or not. There would be an application process, but it's advertised as being fairly easy to get through.
Of course, there's a pragmatic aspect to the whole thing as well: with Spain's economy still straggling, calling in hundreds of thousands of people, millions perhaps, and offering them citizenship out of the blue would provide a nice bump to the talent pool. Although on the other hand, that fact may keep some potential beneficiaries away.
But even if there is a pragmatic motive to it, it's still a nice move. Now if they could just do the same for the Muslims (aka Moriscos), who were booted out in precisely the same fashion in 1609, have yet to get similar recourse, and who would very much like said recourse since we're on the subject and everything, that'd be spectacular.