We have a lot of similar names on the English Wikipedia - http://en.wikipedia.org/w/index.php?title=Special:Listusers&limit=50&...
There's no policy specifically against it even there, and certainly not one that applies across all Wikimedia projects. It's up to each community to decide whether such names are appropriate and whether to block them all or take them on a case by case basis. If someone is otherwise making useful edits, perhaps it's not a problem, but if they're only there to promote whoever they are advocating voting for, it could be a problem.
http://en.wikipedia.org/wiki/Wikipedia:Username forbids (on the English Wikipedia only) names that promote a company, but not those that promote a person.
Angela