Can I deduct expenses paid for a middle schooler to go to Washington DC via a school sponsored trip? Expenses were paid by student.

For MN, yes, they are qualifying expenses. however, the instructions do not address who can pay the expenses on behalf of the child, they only state the taxpayer, which would be the people filing the return, not the dependent. 

"Qualifying expenses include: ... Expenses paid for field trips, including entrance fees to exhibits" https://www.revenue.state.mn.us/individuals/individ_income/factsheets/fact_sheets_fs8.pdf

(Edited 4/7/19 @ 3:02PM EST)