INDIANAPOLIS (AP) — Indiana Democrats face stiff challenges in Tuesday’s election as they try to hold a U.S. Senate seat and cut into the Republican Party’s grip on most congressional seats.

Sen Joe Donnelly is locked in tough fight with GOP businessman Mike Braun in a race that saw two campaign appearances for Braun by President Donald Trump and one for Donnelly by former President Barack Obama in the waning days.

Indiana’s nine U.S. House seats are up for grabs, but only two GOP-controlled ones are considered in play. One is in southern Indiana, and the other is in the northwestern part of the state where Obama appeared Sunday in a get out the vote drive.

Three other statewide races — those for secretary of state, state auditor and treasurer — are on the ballot. Voters also will decide whether Indiana’s constitution should be amended for the second time in two years.

Here are some of the key races:

U.S. SENATE RACE

The neck-and-neck contest between Donnelly and Braun has bombarded Hoosier voters with weeks of advertisements touting competing claims about foreign outsourcing.

Ads targeting Braun, a multimillionaire auto-parts magnate, have focused on his company importing the products he sells from China. Those aimed at Donnelly have focused on a factory in Mexico that’s owned by a company Donnelly’s family owns.

PENCE’S BROTHER

Greg Pence, an older brother of Vice President Mike Pence, is expected to win the heavily Republican 6th District seat his famous sibling once held.

The 61-year-old owner of two antique malls faces Democrat Jeannine Lee Lake, who publishes a bimonthly Muncie newspaper.

The eastern Indiana seat is open because Republican U.S. Rep. Luke Messer ran in the GOP primary for the U.S. Senate. Greg Pence is one of Mike Pence’s three brothers.

COMPETITIVE HOUSE RACES

Political observers say Republicans will likely hold onto the seven Indiana congressional seats they control and Democrats the two others.

But the races for the 9th District, which extends from the Ohio River to the south Indianapolis suburbs, and the South Bend-area 2nd District — are deemed competitive and could possibly change party hands if a Democratic “blue wave” reaches Indiana.

Republican Rep. Trey Hollingsworth faces Bloomington attorney Liz Watson in the 9th District, while Republican Rep. Rep. Jackie Walorski faces Methodist minister-turned-health care company executive Mel Hall in the 2nd District.

LEGISLATURE

Half of the seats in the 50-member Indiana Senate and all 100 seats in the Indiana House are up for election this year.

Republican supermajorities in both chambers have left Democrats largely powerless over the past six years.

Several longtime legislators decided not to seek new terms this year. Democrats need to add four House seats to break the current 70-30 Republican supermajority, while the GOP’s 41-9 Senate margin means Democrats must pick up at least eight seats.

BALANCED BUDGET AMENDMENT

Voters will also decide a ballot measure that would require the General Assembly to pass balanced budgets unless supermajorities of two-thirds of the members of each chamber vote to suspend that obligation.

Indiana’s electorate last voted to amend the constitution in 2016 when it approved a provision to protect the right to hunt and fish.