NASHVILLE (AP) — Five things to know about Thursday's primary elections and other ballot issues in Tennessee:

1. RACES TO WATCH

The U.S. Senate primary has brought some of the sharpest duels. Tea party-backed candidate Joe Carr is seeking to upset Republican Sen. Lamar Alexander, who appears to have a clear edge but certainly cannot ignore the unexpected tea party gains in other states. In the state's 4th Congressional District, incumbent Rep. Scott DesJarlais is seeking to fend off a strong GOP primary challenge after a series of sex scandals.

2. BALLOTS IN THE BAG

Early voting brought out record numbers. More than 550,000 ballots were cast from July 18 through Aug. 2. The Tennessee Secretary of State's office says that is a new high for the state. Results from the early ballot are announced after polls close.

3. STATE RACES

Dozens of Republicans and Democrats face primary challenges in the state legislature. On the GOP side, several incumbents face strong challenges after comments that stunned even supporters. Among the lightning-rod figures is state Sen. Stacey Campfield of Knoxville, who compared the federal health care law to the forced transportation of Jews to concentration camps during World War II.

4. JUDGING JUDGES

A well-funded campaign to oust state Supreme Court judges has brought rare attention to a normally routine part of the ballot. A Republican group, led by Lt. Gov. Ron Ramsey, is targeting three Democrat-appointed judges up for a yes-no "retention" election. In Tennessee, the governor appoints justices and voters decide whether to keep them for full eight-year terms. Even if one judge is rejected, it could give Republicans control of the highest court in Tennessee — an important change in the only state where Supreme Court justices pick the attorney general.

5. VOTING HOURS

Tennessee straddles two times zones, giving some counties flexibility on when to open voting. But polls close at the same time: 8 p.m. EDT and 7 p.m. CDT.