SALEM, Ore. (AP) — By the time Oregonians cast their ballots, the issues and candidates will be well-known. Gov. John Kitzhaber's cowboy boots and Senate candidate Monica Wehby's surgeon scrubs will be all over television. But here are five things you might now know about the upcoming election:

— UNDER-THE-RADAR BALLOT MEASURE

Oregon's constitution says a single person can't hold a position in more than one branch of government. The governor can't be a legislator. The Senate president can't sit on the Supreme Court.

These separation of powers requirements, however, have led to some interesting consequences. Judges can teach at the private Willamette University law school, but not the University of Oregon law school, which is an arm of the executive branch. They can't serve for pay in the National Guard.

Measure 87 would ease up on the separation of powers, allowing state judges to serve in the Guard or teach at a public university.

The measure was put on the ballot by state lawmakers, not signature-collecting petitioners, and it's received very little publicity.

— REPUBLICANS AND DEMOCRATS AGREE ON SOMETHING

Another ballot measure is getting much more attention, in large part because it has moneyed and powerful interests staunchly on both sides. Among them: both the Democratic and Republican parties, and a couple of small parties too.

Turns out, the parties can play for the same team when their own influence is at stake.

Measure 91 would take Oregon to the election system used in California and Washington. The two candidates who get the most votes in May — regardless of their party — advance to the November general election.

Proponents say they're trying to tamp down extreme partisanship and allow all voters to have a say in the field-thinning May primary.

The political parties — joined by many of their interest groups — say it would reduce choice in November. Only two candidates would be on the ballot. Neither is likely to be from a minor party, and both could be from the same party.

— SHRINKING POLITICAL PARTIES

The Republican and Democratic parties are shrinking.

Since the 2010 election, the number of registered voters has expanded 4 percent. But the number of Democrats has dropped 5.2 percent and the number of Republicans has dropped 1.5 percent.

Meanwhile, the number of voters who are unaffiliated or registered with a minor party has jumped 24 percent in the last four years.

— STATE SENATE UP FOR GRABS

The races for Senate and governor, as well as the high-profile ballot measures — pot legalization, food labeling — will grab most of the attention going into November. But in a few parts of Oregon, voters will have quite a bit of say over the makeup of the state Legislature.

Democrats currently have a 16-14 edge in the state Capitol's upper chamber. A Democratic-held seat in Medford and a Republican seat in Albany and Corvallis will be ground zero in the fight for control of the Senate, and both parties are trying to find a handful of other races where they might be competitive.

STATE HOUSE UNLIKELY TO FLIP

For all the intrigue over control of the Senate, the state House is unlikely to flip.

Democrats have a healthy 34-26 advantage and the help of district boundaries that favor their incumbents. They could gain or lose seats in the election, and Republicans are fighting hard to make inroads. But absent a massive Republican wave, flipping up five seats to grab the majority is a tall order for the GOP.

The battlegrounds, as is typical, will be centered primarily in the Portland suburbs.