What were the builders of the Tower of Bavel thinking?

How could people presumably aware of Hashem think they could somehow stand in opposition to Him?

The “Mei Marom” (R’ Yaakov Moshe Charlop, zt”l) offers a tantalizing thought: The place on earth called Bavel possessed a deep spiritual nature of “overcoming the Divine” – which eventually expressed itself properly in the cases recorded in the Gemara (e.g. Bava Metzia 59b, Rosh Hashana 57b) where a beis din “overruled” Hashem – that is to say, asserted the ability He gave Klal YIsrael to do so.

Perhaps, Rav Charlop suggests, it was that spiritual reality of the place that inchoately resonated with its inhabitants, leading them to feel that, indeed, in their own way, they had the “ability” to challenge Hashem.