"Now at this time Caesar Augustus issued a decree for a census of the whole world to be taken. This census -- the first -- took place while Quirinus was governor of Syria, and everyone went to his own town to be registered. So Joseph set out from the town of Nazareth in Galilee and traveled up to Judaea, to the town of David called Bethlehem, since he was of David's house and line, in order to be registered together with Mary, his betrothed, who was with child."
According to Jim Bishop (The Day Christ Died and The Day Christ was Born) it is about ninety miles from Nazareth to Bethlehem, and the Holy Family traveled this on foot (well, Jesus didn't, but you know what I mean).
And for what?
The spiritual reason they went to Bethlehem was so Jesus would be born there, to fulfill the prophecy, of course. (That should go without saying.)
The worldly reason they went there, was so Caesar Augustus would know how many subjects he had, so he could tax them.
Even had he known about this young carpenter and his very pregnant wife traveling ninety miles on foot, would he have cared? Somehow I doubt it. Caesar didn't give orders for his subjects' convenience.
And that, folks, is what imperial government is like. It sure isn't "of the people, by the people, and for the people."