Why don't the democrats just barge into the locked agencies?

Nobody has answered this question and it has been bugging me for a week. Why don't congress members just demand to be let in to the USAID/ Department of Education/ Department of the Treasury etc...

Do they not have legal standing to call the police to arrest anyone blocking their entrance as members of congress?

Are the police behind the doors of the Education Department breaking the law themselves?

I'm not posting this as a rhetorical question to hint at my opinions on Democratic inaction, or to vent frustration. I am literally interested in what are the political and/or legal reasons they have not done these things. Please only answer if you have knowledge on the subject.