Dad Blocks Superintendent from Daughter at Graduation, Motives Questioned

A Wisconsin dad is under fire for rushing the stage at his daughter's high school graduation to shove a school official from the handshake lineup ... and some think race is involved.

This went down at Baraboo High School last week, when they were holding their ceremony for the outgoing seniors -- and video captured this awkward moment ... when a girl was walking across the stage and preparing to shake hands with school district bigwigs.

The superintendent, who's Black, is at the end of the line and he's ready to put 'er there -- but the girl's father pops up out of nowhere from the crowd, whisking him away fast.

You can tell the impromptu interruption caught everyone off-guard -- including his own kid -- and while they're off camera ... you can hear what sounds like the father say "I don't want her touching him" ... this while the superintendent, Rainey Briggs, expresses frustration.

It all ended with the father -- whom we're not identifying to protect the girl's identity -- getting arrested and booked on a disorderly conduct charge ... but his motives remain unclear.

Baraboo PD tells TMZ ... a resource officer who was on campus at the time ended up detaining the dad and he was eventually taken to a room for questioning -- where we're told cops asked him why he did what he did ... but the dude wouldn't offer a clear reason.

BPD says the father offered a vague rationale that didn't specify what his beef with Briggs was -- and the cops go on to say they won't speculate on the motivations here either.

That's not stopping others from jumping to conclusions though -- including a state representative named Francesca Hong ... who straight up labeled it racist and vile.

She wrote, "Dr. Briggs is an excellent superintendent who cares deeply about the well-being of all students in the Baraboo District. No one should have to endure this type of gross and racist conduct."

BTW, local reports say the district at large has been ensnared in controversy of late ... so again, it's unclear what exactly this was really about. We tried hitting Briggs for further clarification, but he didn't wanna talk. We haven't been able to reach the dad.