8 years ago, I had a Dodge Dakota with a 3.9 V6 in it. I had a Class III hitch, and was towing back a U-haul trailer LOADED with surplus from Mechanicsburg PA. The trailer was carrying at least four tons of heavy items from the DRMO there. I took the trip very slowly, but as I got further south, the clouds started building up and a little rain fell, just enough to make the road surface slick. Wouldn't you know it, after the rain stopped (but the road was still wet) I approached a light with about four people waiting. I applied the brakes and nothing happened. Pretty soon, the brake pedal was on the floor, all wheels locked and I was skidding toward the cars. I missed the back bumper of the car in front of me by 1 or 2 inches. TOO hairy.
After the fact, I figured that I just had bit off more than I can chew, and overblew the safe towing capacity of the truck. The key word is SAFE. You have to think not just about "is it safe for me to haul this and not get hurt?", but you have to think about "is it safe for me to haul this and not hurt others?" I should have taken two trips and been safe, rather than try and cram it all in and overload the trailer. I could've gotten in an accident that day, and any cop in this country would have ruled it my fault if I hurt someone else, regardless of road conditions (the "Act of God" clause in most insurance policies only go so far - if you get in an accident on a slippery road surface that could have been prevented if you hauled a smaller, safer trailer, don't expect them to cover your butt in that instance).
My advise, DO NOT use the Blazer to haul that backhoe. In fact, I wouldn't haul more than half the weight of the Blazer behind your M1009. If the Blazer weighs 5,200 lbs, your max safe towed load should be 2,600 lbs.