Unless they're appointed by a governor to fill in for a second-in-command who has died or resigned, lieutenant governors are usually elected into office by voters. In some states (Maryland is one example), they run on a ticket with the gubernatorial candidate of their political parties [source: State of Maryland]. In other states (California is one example), they're listed on the ballot separately [source: State of California]. When they're listed separately, it can lead to an awkward situation in which the governor and the lieutenant governor represent opposing parties, which, as you might imagine, doesn't do wonders for their ability to work together.
For example, in the late 1970s, Republican Mike Curb -- a music producer who penned the commercial jingle "You Meet the Nicest People on a Honda (Go Little Honda)" -- was elected second-in-command to liberal democratic Gov. Jerry Brown [source: Mikecurb.com]. While Brown was absent from the state for long stretches during an unsuccessful presidential run, Curb took his place and used his authority to appoint judges, which created a political mess for Brown [source: York].
There aren't a lot of career prerequisites for lieutenant governors. Curb worked the entertainment industry, while former Virginia Lt. Gov. Don Beyer sold cars [source: Kumar]. Mike Huckabee, who was elected Arkansas lieutenant governor in 1993 and eventually became governor, was a Baptist minister [source: Orlando Sentinel].
A lot of lieutenant governors have backgrounds serving in other government posts. Delaware Lt. Gov. Matt Denn was his state's insurance commissioner [source: State of Delaware]. A peculiar quirk in Pennsylvania's constitution allowed Joe Scarnati to ascend to lieutenant governor and still keep his seat in the state Senate [source: State of Pennslvania]. Sean Parnell, who became governor of Alaska when Sarah Palin stepped down in 2009, worked as a legislator and as a private-sector attorney [source: State of Alaska].
In the next section, we'll look at what lieutenant governors do once they're in office.