The wards went off, alerting every Death Eater in the vicinity that there were intruders who had apparated in and there was only one - or three - morons that were stupid - brave - enough to do such a thing. Potter. And his measly friends.
Hogsmeade was immediately filled with Death Eaters, both new and old members of the group, who scattered out and searched for their prey. None of them wanted to admit defeat and many, if not all, were loyal to their Lord but even they had to admit that if he was able to avoid a large number of people hunting just him, then did have they any chance?
They didn't want to presume that their Lord wouldn't be able to handle the schoolboy, but, it had been many years and each and every one of them had the outcome of a young infant, boy who wasn't even a teenager and a teenager, squashing him at every turn.
There wasn't even snow on the streets that would contain their target's footprints so that they could find them easier. Hogsmeade almost always had snow and the one time they need its assistance and it wasn't even there.
They weren't skilled or smart enough to find Harry Potter without some sort of help.
They were all doomed to fail, from the start.
Chocolate Frog Card: Mulciber I (bronze) - prompts; Hogsmeade, presume, defeat, snow