THE POLITICAL CALCULUS in Salem this year has been particularly bedeviling.

Voters last fall sent 30 Democrats and 30 Republicans to the House of Representatives, meaning any piece of legislation intended for the governor's desk needs at least one GOP vote, or 31, to pass.

But that's not even the half of it. To get even that far in the divided House, bills also must navigate a complicated power-sharing structure. Both parties agreed to elect co-speakers—Arnie Roblan, D-Coos Bay, and Bruce Hanna, R-Roseburg. And each co-speaker named a co-chair to each legislative committee.

And that means, instead of 31 votes, the deciding number is really just one. As in, any one of those co-chairs, or the co-speakers, can doom a bill. And this year, so far, it's been the Republicans eagerly wielding the scythe.

"Bills that had bipartisan support in the Senate can't even get out of a committee on the House side," says Scott Moore, communications director for progressive advocacy group Our Oregon. "That's the definition of partisan gridlock."

To illustrate his point, Moore sent over a list of bills and resolutions that emerged from the Senate (where Democrats have just a 16-14 advantage) with bipartisan support—some unanimously. A few are controversial—bans on toxic chemicals or adding more checks to insurance rate hikes. Others aren’t: They would give veterans a day off on, um, Veterans Day, or name a National Guard center after former Governor Ted Kulongoski.

Here are a handful of bills with good odds of passing that've been trapped, instead, by the Capitol's partisan vortex.

Tuition Equity: Senate Bill 742

Immigration-reform advocates gave a mighty cheer in March when the groundbreaking tuition equity bill passed the Senate, applauding the plan to allow children of undocumented immigrants who graduate from high school in Oregon to pay in-state tuition at Oregon universities.

But this Dream Act-like bill remains captive in committee. Representative Michael Dembrow, D-Portland, tried a last-ditch effort, aiming to snag 31 legislators' signatures on a procedural petition that would force an up-or-down vote on the bill, but it failed.

"It's an issue that should transcend politics, and yet here in Oregon, it's stuck in politics," says Dembrow. "Everything that touches upon immigration policy is toxic."

Reviewing Rate Hikes: Senate Bill 718

Senator Chip Shields, D-Portland, doesn't think it's a stretch that health insurers, when they raise premiums by more than seven percent, should have to notify their customers. He also wants regulators to explain, when approving any increase, why they ruled the way they did. The hope is to give small businesses and citizens more of a say in increases.

Shields persuaded 24 other senators to support his plan—the only one of three health insurance bills he proposed this session to clear the Senate. But in the House? The bill is languishing.

"The health insurance lobby has really shown an unwillingness to negotiate," Shields says.

No BPA for Babies: Senate Bill 695

This bill, which would ban toxic chemical and potential carcinogen bisphenol-A (BPA) from sippy cups and other plastic kids' products, managed to clear the Senate 20-9. Then it got stuck in committee in the House—with co-speaker Hanna, who owns a Coca-Cola bottling distributor in Roseburg— reportedly refusing to spring it free.

(A spokesman for Hanna wouldn't comment on that, saying only "both sides win some and lose some.")

Representative Ben Cannon, D-Portland, also tried a petition. But he fell short of the 31 signatures, and the bill died. Cannon has introduced a substitute bill, HB 3689—and counts some Republican colleagues as sponsors who didn't support his petition. That bill, meanwhile, has yet to advance.

"When you when add it up, you get to 31," he says. "It should be pretty hard to make the case that a bill that has majority support shouldn't come to the floor."

Ban the bag: Senate Bill 536

(This plight of this bill, which actually cleared the House but not the Senate, is more traditional.)

Banning plastic checkout bags from big Oregon grocery stores stormed into the legislature this winter with support from a surprising coalition of environmental and business groups, riding a wave of enthusiasm after Portland passed a local ban last year (it hasn’t kicked in yet).

But the anti-trash measure looks like it will die under the pressure of intensive lobbying. The bill’s main opponent, plastic bag recycling company Hilex Poly (which has no plants in Oregon), spent a total of $52,000 on four lobbyists during the first three months of the legislative session. In contrast, the bill’s strongest proponent, the Surfrider Foundation, reported a measly $68.75 worth of lobbying.

The ban, currently stalled in a Senate committee, is also struggling because it’s viewed as purely environmental in a year been all about the economy. “It's frustrating to not have it get more traction even after 500 Oregon businesses in support,” says Surfrider’s Gus Gates.