(Cross-posted here.)

Greg Mackay, the Knox County Administrator of Elections, sent out an email this afternoon asking folks to help explain Tennessee's primaries and how they work.

Here's the body of Greg's email (which I'm posting with his permission). The emphasis is mine:

The February election is a primary election.

In Tennessee, we have an "open" or "pick-a-party" primary election. A registered voter may vote in either party's primary. The voter can select which party's primary they wish to vote in on Election Day. Tennessee voters do not pre-register with a party before the primary.

While you can choose which party primary you wish to vote in February, you cannot "crossover," or vote in both. Some people may want to select a person of one party [in the primary] for President and a person of the other party [in the primary] for a local office. That is not allowed in Tennessee. You can only vote in one primary: Democratic or Republican.

When you vote in February, the workers will ask you in which primary do you wish to vote: Democratic or Republican. While it may seem frustrating, we will need to know which primary you wish to vote in.

Any independent candidates will skip the February primary and go straight to the August ballot. In the general election in August, you can crossover and vote for persons of either party.

So, this means that in a primary, you can only vote for candidates from one party, from local all the way up to state and national offices. On the day of the general election, of course, you can vote for whomever you choose regardless of party, but for the primary races, you'll either be voting on the Republican ticket or the Democratic ticket.

To complicate matters a bit, August 7th is the general election in Knox County for county offices only (the primary having been in February), and it is also the primary for the US House of Representatives and certain seats in the Tennessee state legislature. As with the February 5th primary, the election in August will require voters to declare which primary they're voting in, but this party identification only applies to the primary races; on that day, you can still vote for either party in the general races.

This PDF at the Tennessee Division of Elections lists the various election dates for 2008. Note that some counties hold their primaries for county office on May 6th instead of February 5th.