Sheldon Adelson was the biggest Republican donor in the 2012 election. Now he's lobbying to curtail online gambling. Why? Presumably because online gambling would compete with his business: casino gambling.

Some industry insiders think online gambling could bring new people into the worlds of poker and gaming, and thus new customers to casinos. Others see online gaming as a direct competitor that steals customers from casinos. (What serious poker player would play one table, at 20 to 25 hands per hour, when he could play 6 tables at 75 hands per hour?)

Put yourself in the mind of a casino owner. However you think this will affect your industry, you have to assume online gambling will matter. More entrepreneurial executives in any industry adapt to the Internet -- see Walmart becoming on online retail powerhouse; see Jack Welch's "destroy your business" campaign.

An alternative to adapting to new technology is to call in government to prevent competitors from using that technology from competing with you.

Many casinos are taking a middle road: embracing online gambling, while also calling in government to keep out new entrants.

Adelson seems to be taking the hard line, though, spending big to launch the Coalition to Stop Internet Gambling. Via Forbes:

My moral standard compels me to speak out on this issue because I am the largest company by far in the industry and I am willing to speak out. I don’t see any compelling reason for the government to allow people to gamble on the Internet and nobody has ever explained except for the two companies whose special interest is going to be served if there is gaming on the Internet, Caesars and MGM.

This is often the nature of regulation: a tool incumbent businesses use to protect themselves from competition — to the detriment of consumer choice, entrepreneurs and less politically connected competitors.

But if we give Adelson some benefit of the doubt, we could see his view this way: Gambling, done right, is great entertainment. Done wrong, it's corrosive to society. So Adelson has a big interest in guaranteeing it's done right.

This is the regular argument given by usually free-market businesses calling for more regulation: protecting the industry from unsavory fly-by-night types. H&R Block makes this case. So do pubs in the UK.

If Republicans start sounding more pro-regulation than they normally do, don't be surprised. After all, in this case, regulation is "pro-business." Specifically, pro-Sheldon Adelson's business.