Well, a lot of bars across the country that have forced smoking bans are caught letting their patrons smoke.
The bar owners are issued a fine. Sometimes, the smoking patron is also fined. But I have never heard that their liquor license was taken away or even threatened.
Markamn is correct about the liquor licenses.
Many, many places have had their liquor licenses threatened, and some places have lost them over the smoking bans.
In Delaware, for example, if you have 3 violations of ANY law, not just liquor laws, or smoking bans, or health codes - a liquor license holder is brought before the Alcohol Commission and can lose their liquor license. They are the only businesses that can be put out of business for violating the smoking bans.
It is the reason I have always stated that smoking bans are a back door to prohibition. A bar without a liquor license is no longer a bar.