At first, Sen. Bernie Sanders’s tone with Donald Trump was conciliatory: “To the degree that Mr. Trump is serious about pursuing policies that improve the lives of working families in this country, I and other progressives are prepared to work with him,” he said in a statement after Election Day.

Then he saw Trump’s infrastructure plan.

Sanders’s tone changed; he tweeted that the president-elect’s plan for infrastructure is a “scam,” proving just how difficult working with a Trump administration will be in practice:

Trump's plan to repair our infrastructure is a scam that gives massive tax breaks to large companies & billionaires. https://t.co/05JEyOwddR — Bernie Sanders (@SenSanders) November 21, 2016

Sanders went on to write:

During the presidential campaign, Donald Trump correctly talked about rebuilding our country’s infrastructure. But the plan he offered is a scam that gives massive tax breaks to large companies and billionaires on Wall Street who are already doing phenomenally well. ... Unlike Trump’s plan, which creates new tax loopholes and is a corporate giveaway, my Rebuild America Act would be paid for by eliminating tax loopholes that allow hugely profitable multinational corporations to stash their profits in offshore tax havens around the world.

To many Democratic politicians, infrastructure was theoretically one of the few areas where working with President-elect Trump seemed feasible: “Surprisingly, on certain issues, candidate Trump voiced very progressive and populist opinions,” soon-to-be Senate Minority Leader Chuck Schumer told NBC’s Chuck Todd Sunday. “For instance, getting rid of the carried interest loophole, changing our trade laws dramatically, a large infrastructure bill.”

But as Sanders’s blog post and tweet showed, their ideas don’t line up all the way.

Take infrastructure, for example. As Vox’s Brad Plumer explained, as much as Trump loves the idea of infrastructure, his plan wouldn’t actually do much to fix American infrastructure:

What Trump has right now is an idiosyncratic proposal for Congress to offer some $137 billion in tax breaks to private investors who want to finance toll roads, toll bridges, or other projects that generate their own revenue streams. But this private financing scheme, experts across the political spectrum say, wouldn’t address many of America’s most pressing infrastructure needs — like repairing existing roads or replacing leaky water mains in poorer communities like Flint. It’s a narrow, inadequate policy.

That’s not going to cut it in a bipartisan bargain. Sure, the big ideas on these policy issues, like improving infrastructure, striking fair trade deals, and closing unfair tax loopholes, are notions both parties agree on.

The problem is that’s a facile conciliation. When it comes to drawing up policy, there’s going to be a bit more of a fight.

Further reading: Donald Trump's infrastructure plan wouldn't actually fix America's infrastructure problems