Federal tax liens on foreclosure

[Jeremy England]

So i'm researching properties to buy at the county foreclosure auction.  I came upon one that looked promising (like 40k difference in lender's max bid and value) but when I searched the title I found like 35k in federal tax liens.  

So is this a deal breaker for most of you?  Is there a method of negotiating these liens down?  

Not going to move on this one but I'd like to know for future reference