If you pay a private citizen money to use their influence to get the government to do something, that's lobbying. However, if you pay a government official to do something, that's bribery.
Utah's newly inaugurated Attorney General John Swallow is accused of facilitating (lobbying) a failed attempt to bribe a U.S. senator while Swallow was a public servant. Regardless, he was paid a hefty "consulting fee" while he was the previous attorney general's top dog.
Swallow says the fee that was paid to his lobby firm (which never registered any lobbyists) was to get a cement factory in Las Vegas.