Things got a little tense during the June 7 committee hearing on Oregon’s proposed transportation package, with Sen. Brian Boquist (R-Dallas) publicly blasting SEIU 503 president Steve Demarest for “political blackmail” over his union’s threat to sabotage the plan at the ballot box if the Legislature doesn’t come through with what it really wants.

What it really wants is a corporate tax hike — the reasons for which we’ll get to in just a minute — and like something they learned watching House of Cards, the political operatives of SEIU 503 appeared to think that threatening to derail the much-needed transportation package would force lawmakers into action.

Unlike the antagonists of the award-winning TV series, however, real-life blackmailers don’t always command the room.

“You’re trying to play political blackmail, that’s what you’re trying to do” announced Boquist, who originally wasn’t going to speak up. “And I sit on both committees. If you want to generate ‘no’ votes across the board, you continue this crap, do you understand me? ... and you take it back to your union members, and you tell them to decide, they come to the table to negotiate and work, or they get out.”

The lecture came after Sen. Betsy Johnson (D-Scappoose) asked Demarest to comment on whether SEIU 503 was “really willing to sacrifice” the bipartisan effort aimed at raising funds to improve Oregon’s roads, bridges and other infrastructure.

“We don’t believe the transportation package can go through without revenue reform,” was the union president’s reply.

While Demarest didn’t stray into specifics, SEIU 503’s political director had confirmed to The Oregonian a day earlier that if the transportation package does pass, the union would indeed consider funding a ballot measure to take it down.

Ironically, SEIU 503 claims to be in favor of the transportation package itself, which might be true. But while union leaders probably believe this makes them look better — after all, they’re only threatening to undermine it to achieve the greater good of making businesses pay more taxes — the reality is that it only serves to show the level to which they’ll stoop to accomplish their political agenda.

And despite the voters’ resounding rejection of Measure 97 last fall, that agenda remains fixed on a corporate sales tax.

Which brings us to the why.

Beyond the mere fact that SEIU 503’s blackmail tactics are wrong, there are deeper truths to be gleaned from the union’s behavior. After all, why would it be willing to threaten the transportation package in the first place? If the union wants to raise corporate taxes that badly, it could simply try again at the ballot — or join the OEA’s campaign — to accomplish that goal.

One answer is that SEIU 503 probably has more faith in attempting to manipulate the Legislature than it does the voters.

The other is that SEIU 503’s true priority, and a self-serving one at that, lies in creating bigger government. So much so that it’s willing to throw private-sector union jobs like those that would be created by the transportation plan under the proverbial bus.

More than anything, this serves to expose the fundamental disconnect between public-sector and private-sector unions.

SEIU 503 has a strong foothold representing state workers, and it just so happens any corporate gross-receipts tax — as the Legislative Revenue Office (LRO) demonstrated with Measure 97 — would significantly increase government job growth, as new programs and positions are created to handle the tax revenue. With the ability to unionize on its home turf and require these workers to pay union dues and fees, SEIU 503 stands to gain millions of dollars in additional revenue each year.

The LRO also determined the tax would hurt private-sector (and overall) job growth. But no matter. Consistent with its threat to sabotage the Legislature’s transportation package, SEIU 503’s investment appears to be not so much in the people of Oregon as it is in the Oregon government.

The transportation package, if passed, would undoubtedly create jobs for private-sector union members contracted to complete the road-fixing work. But although unions in both sectors often claim to hold the same priorities, SEIU 503’s attempt at “political blackmail” reveals their differences.

Its willingness to hurt private-sector union jobs for the sake of its own self-interest is a striking example of the very different — and very problematic — priorities that can take hold when a union’s primary financial stake is in the government.

If SEIU 503 is truly in it for “all working people,” and if it truly believes a transportation package is needed, it wouldn’t hold the entire state hostage for what it really wants — more money for itself.

— Ben Straka is a labor policy analyst for the Freedom Foundation.