(AP) - Delaware voters are deciding who will fill two of the three seats held by the state's congressional delegation and three statewide elected offices, as well as whether Republicans gain control of the state Senate for the first time in decades.

Currently, Democrats hold all three of Delaware's congressional seats, the attorney general's office, and control of both chambers of the General Assembly. Republicans are hoping they can hold on to the state treasurer's office and state auditor's office, score upset wins in U.S. Senate and House races, and take control of the state senate for the first time since 1973.

Here is a look at the key races in Delaware:

U.S. SENATE

Incumbent Democrat Tom Carper is seeking a fourth-term in the U.S. Senate as he seeks to keep his unbeaten string during more than four decades in politics intact. Carper is running against Sussex County Councilman Rob Arlett, who owns a real estate business and was President Donald Trump's state campaign chair in 2016. Also running are Green Party candidate Demitri Theodoropoulos, a record store owner in Newark, and Libertarian candidate Nadine Frost, a political activist who ran for Wilmington city council two years ago.

U.S. HOUSE

Incumbent Democrat Lisa Blunt Rochester, the first black and first woman elected to Congress from Delaware, is seeking a second term as the state's lone representative in the U.S. House. She is being challenged by Republican Scott Walker, a businessman who ran for Congress two years ago as a Democrat and has been disavowed by the state GOP for his controversial statements.

ATTORNEY GENERAL

Democrat Kathleen Jennings, a former state prosecutor who also held the number-two job in Delaware's Department of Justice, is now vying to become attorney general. Her Republican opponent is Bernard Pepukayi, a longtime Democrat who switched parties and filed for the office after the lone GOP candidate abruptly quit the race. Incumbent Democrat Matt Denn opted not to seek re-election.

TREASURER

Republican Ken Simpler is seeking a second four-year term as state treasurer, an office that has been used in the past as a stepping stone to higher office. Simpler, who has a long background in the finance industry, is being challenged by Democratic newcomer Colleen Davis, a health care industry consultant.

AUDITOR

Incumbent Republican Tom Wagner's decision to retire for health reasons has given Democrats the chance to claim the state auditor's office for the first time since 1989, when Wagner first took office. Democrat Kathleen McGuiness, a businesswoman and longtime Rehoboth Beach commissioner, is vying for the seat against Republican James Spadola, a military veteran and former Newark police officer who has an MBA degree and a background in finance. Less than three weeks before Tuesday's election, Wagner appointed Spadola to fill the vacant post of deputy auditor, drawing complaints from Democrats of political favoritism and partisanship.

DELAWARE SENATE

Democrats currently control the Delaware Senate by a narrow 11-10 margin, but Republicans are hoping to regain control of the chamber for the first time since Richard Nixon was president. Republicans have a chance to unseat two incumbent Democrats in northern Delaware but are setting their sights on a seat in central Delaware left open by a Democratic lawmaker's retirement. That race pits Republican Justin King, a businessman and mayor of Camden, against Democrat Charles "Trey" Paradee III, a financial adviser who gave up his state House seat to run for Senate.

DELAWARE HOUSE

All 41 seats in the state House are on the ballot, but 13 candidates, roughly a third of the total, face no opposition and are guaranteed to take the oath of office.

VOTING

Polls are open from 7 a.m. to 8 p.m.