What if
King Rudolph I had managed to successfully install his son
Albert as successor of the assassinated King
Ladislaus IV of Hungary? With Hungary under his belt would Ruldoph had been able to get his son elected as Emperor of Germany? If so then could Albert have had enough power to install a hereditary monarchy over with the Habsburgs as Emperors of a New Western Roman Empire?
It would have been difficult to be successful at installing Albert in Hungary; Albert's attempt to install his son Rudolph in Bohemia was easier, because Albert was king of the Romans during that attempt and Bohemia was a part of the Empire. Although with the early death of Rudolph during the campaign to secure Bohemia that also became a failure. (If the Habsburgs would already control Hungary, then if the same opportunity arises in Bohemia ITTL they'll be in a better position.)
Hungary is a good powerbase and it would have improved the position of the Habsburgs, however during that time most of the prince-electors favoured a relatively weak king. If Albert had established a better relationship with the papacy, he might even be crowned Holy Roman Emperor.
An new hereditary (Holy Roman) Empire is very hard and would have taken a very long time. Besides that, it would have meant a Hereditary title of king of the Romans, the pope won't give up his privilege to crown the emperor.