HELENA — Five things to know about key races in Montana’s primary elections: 

WALSH vs. DAINES: Democrat John Walsh and Republican Steve Daines easily topped their primary opponents to square off for the U.S. Senate seat vacated by Democrat Max Baucus. Walsh’s February appointment to the seat gave him powers of incumbency, but Daines, a first-term congressman, has demonstrated he can win a statewide race. Money from outside groups is pouring into a contest that could help determine which party controls the Senate.

LEWIS vs. ZINKE: Former Baucus aide John Lewis cruised to victory in the Democratic House primary — his first run for office. He opposes former state Sen. Ryan Zinke of Whitefish in the Nov. 4 election for Montana’s lone seat being vacated by Daines. Zinke prevailed in a bitter five-way GOP primary.

THE LEGISLATURE: Most Republican incumbents prevailed in their primary contests despite a rift between conservative and moderate factions that spurred some intra-party challenges. Democrats fielded at least one candidate in every race as they seek to win back control of at least one of the two legislative chambers. This year’s election is the first since legislative districts were redrawn after the 2010 U.S. Census.

JUDICIAL ELECTIONS: All Supreme Court candidates advanced to November’s election. Justice Jim Rice faces W. David Herbert and Justice Mike Wheat squares off against former Solicitor General Lawrence Van Dyke, whose eligibility to run faces a legal challenge. Nine district judgeships were up for election, including the Billings seat vacated by new U.S. District Judge Susan Watters.

PUBLIC SERVICE COMMISSIONER: Former Secretary of State Brad Johnson of East Helena won the District 5 Republican primary for the panel that regulates utilities. Johnson defeated Derek Skees and John Campbell. Johnson faces Democrat Galen Hollenbaugh of Helena, who was unopposed. Chairman Bill Gallagher is not seeking re-election. Commissioner Travis Kavulla of Great Falls, a Republican, will be unopposed in the District 1 general election.