Was Mitch McConnell onto something?

Democrats have spent years bemoaning the Senate majority leader's reflexive obstruction of President Obama's agenda, but now that they're the ones out of power, they might need to become the "Party of No" themselves.

It was easy to chalk up McConnell's obstruction to raw cynicism, but there was a very specific theory behind it. "We thought — correctly, I think — that the only way the American people would know that a great debate was going on was if the measures were not bipartisan," McConnell once explained. "When you hang the 'bipartisan' tag on something, the perception is that differences have been worked out, and there's a broad agreement that that's the way forward."

In other words, if things are going well — if Congress is passing legislation, if problems are getting solved and livelihoods and communities are improving — then voters assume the country is on the right track, and that the people in power are doing a good job and should stay there. Conversely, when there's gridlock and the economy isn't doing well, voters assume the people in power — usually understood as the president's party — need to be given the boot.

That's why, after years of forcing gridlock, Republicans were just rewarded for years of hostage-taking over Congressional budgets and the debt ceiling with total control of Congress and the presidency.

So, by all accounts, McConnell's theory has been a smashing success.

You can write this off as a raw power grab. But we don't take ideologies and worldviews seriously enough in American politics. The Republicans have a set of values about how resources and power should be distributed, and how communities should be ordered. The left in general and Obama's agenda in particular — the stimulus, ObamaCare, financial reform, etc. — stand in opposition to those values. Had McConnell and the GOP cooperated, they would have sent the message that liberalism works — that it was putting the country on the right course. It should be perfectly apparent why many in the GOP found this prospect abhorrent.

This brings us back to the Democrats, and the horrid dilemma that Trump's victory places them in.

Trump is an empty vessel when it comes to ideology, so it's likely he'll just rubber-stamp the GOP's existing agenda: Massive tax cuts for the wealthy; the destruction of ObamaCare, Dodd-Frank, and the welfare state; and an infrastructure "plan" that might be mostly corporate graft. And in that case Democrats can and should obstruct Trump with a clear conscience.

But what if Trump surprises progressives? Reporting in The New York Times suggests the Democratic leadership is hoping they can make common cause with Trump on things like trade reform, child tax credits, paid maternity leave, and infrastructure spending that would actually work. Bernie Sanders and Elizabeth Warren have sent similar signals. And I myself have argued that Democrats, in their bid to retake power, should embrace economic populism.

But there are drawbacks to cooperation.

Trump campaigned on an agenda of (supposed) populism intertwined with reactionary white nationalism. As liberals keep rightly repeating, this is not normal. Any victories for Trump will show "that there are tangible gains for embracing Trump-style demagoguery" as Jamelle Bouie wrote at Slate. "Supporting a Trump-branded infrastructure initiative as a discrete piece of policy where two sides can find common ground only bolsters a white-nationalist politics, even if you oppose the rest of Trump's agenda. It legitimizes and gives fuel to white tribalism as a political strategy" — just as McConnell's cooperation would have lent fuel and legitimacy to Obama's liberalism.

Make no mistake about it: Forward movement on infrastructure or the child tax credit or those other issues would improve the lives of millions of Americans and relieve enormous suffering. But achieving those ends through bipartisan cooperation with Trump could embolden a movement that seems poised to crack down on Black Lives Matter, deport immigrants en masse, and more. To some degree, Democrats could be buying those victories by throwing African-Americans, Muslims, and immigrants under the bus.

Maybe an organized opposition could get worthwhile policies passed under Trump, while also protecting vulnerable populations. Maybe there's a messaging trick the Democrats could figure out to work with Trump while still denying Republicans credit. I'm not hopeful; both cooperation and total obstruction seem like terrible options. It's a genuine Sophie's choice.

Republican infighting may well save the Democrats and their leadership from this dilemma. But if liberals do have to make this call, they need to understand the reality.