This was always going to happen, and Democrats should be prepared for it.

Stop me if you’ve heard this before, but Republicans are proving themselves untrustworthy in policy negotiations.

About a month ago, 11 Senate Republicans secured a deal with the White House on a subset of infrastructure spending, while claiming to speak for enough of their colleagues to break a filibuster. But now there are murmurs of wavering. CNN reports that five of the 11 are having second thoughts, while Politico gets a couple specific senators on the record with their misgivings. Jerry Moran, a nondescript backbencher from Kansas, is in both pieces, and his presence is notable. Moran’s two complaints are consistent with why this bipartisan deal was always going to be a Lucy-and-the-football scenario.

Moran told Politico that there are "red flags" around using increased IRS enforcement as a revenue-raiser in the deal. The agreement would give $40 billion more in funding to the IRS to reduce the "tax gap" between what people owe and what they actually pay. About $100 billion in revenue depends on this provision in the deal. Moran hinted at conservatives being targeted by a bulked-up IRS, but his concern is obviously political.

The Coalition to Protect American Workers, a dark-money group helmed by Mike Pence’s former vice-presidential chief of staff Marc Short, has been running ads against Moran in his home state, darkly warning of an army of jackbooted government bureaucrats. "If Joe Biden gets his way, they’re coming: IRS agents," the ad intones. Short’s group has set a goal of $25 million for the pressure campaign against Moran and other Republicans.

This is part of a larger mobilization campaign from an all-star team of conservative politicians and far-right groups (among them some of the richest people in the country) that should have been anticipated from the get-go. The entire impulse of anti-tax conservatives for at least 40 years has been to starve the IRS of funding. Around 30 percent of IRS enforcement division staff has been cut since 2010, leading to a withering of its duties. The right was not going to be silent as the agency was propped up with additional resources. And they’ll use any tool available, including the ProPublica leak of high-earner tax information, to prove that this "rogue" agency doesn’t deserve more money.

A related complaint is that the revenue provisions of the deal are phony. Several GOP senators went on the record about that. Of course it’s phony! Republicans won’t raise a dime of tax revenue and they don’t even want to collect taxes already owed. How exactly else would $579 billion of revenue be raised over a decade?

Some of the measures, like unused coronavirus aid, are just figments of the GOP imagination. Democrats are now embracing dynamic scoring—essentially factoring in the economic benefits of spending—which they have savaged for many years when Republicans used it to justify tax cuts. I’d rather phony pay-fors than the privatization of public assets, but since Biden forced all the spending to be offset, you were always going to run into this problem in a bipartisan deal.

The rest of Moran’s complaint was also predictable: that "a bipartisan bill could help kick off a massive subsequent round of spending by Senate Democrats on party lines." The idea that Republicans will only agree to one bill if Democrats agree to never pass another bill ever again is rather absurd, but this was always a question I had. Why would Republicans facilitate the biggest priority of the Biden administration, and give him the opportunity to claim at least a portion of it was bipartisan?

The common thread in these complaints is that Republicans don’t really want to do any kind of bipartisan bill on a Democratic priority. They’re happy to get Democratic support for their priorities, but not the other way around. Looming over this is the overlord of the GOP, Donald Trump, who’s criticized the effort, entirely on the terms that you shouldn’t make any agreement with any Democrat ever. And we’ve endured years of Republicans paying fealty to whatever Trump says. The fact that in the face of this, the White House is courting conservatives on supporting welfare spending seems just crazy.

But let’s recall that signing on to a smaller bipartisan bill for "hard" infrastructure was actually a Republican idea. The theory was that if they gave on the smaller spending package, Democrats would cave in on a larger reconciliation bill with social spending and tax measures, which would require practically all of their members in Congress to agree. If Republicans now pull out the rug on the bipartisan agreement, this could plausibly anger moderate Democrats enough to push them into the arms of the reconciliation package, at which point Democrats get the victory they sought anyway without having to share credit for any of it with Republicans. They could even increase funding for the IRS to Biden’s preferred level of $80 billion, and add back in a host of infrastructure elements cut out of the bipartisan bill.

The question is whether Democrats would get it together to follow through on that threat, which Sen. Tim Kaine (D-VA) made publicly earlier this month, only to face backbiting from anonymous staffers that he was threatening to derail the bipartisan effort. The thrill of bipartisanship still holds far too big a sway among elements of the Democratic caucus.

Meanwhile, on the other side of the dual-track process, Sen. Bernie Sanders’s (I-VT) ambition for a $6 trillion reconciliation package has already been cut nearly in half, and that’s the starting point of the negotiation. That said, what appears to have been excised are the parts that weren’t in Biden’s original proposals. It’s good news that climate and housing measures are in the baseline bill, along with the social spending in Biden’s American Families Plan. And the threat of building the physical infrastructure pieces into the reconciliation package if Republicans go AWOL from the bipartisan bill remains front and center.

Though Senate moderates have been the focus for who holds the ultimate outcome in their hands, if I were to guess I’d say that House moderates will be the bigger obstacle. Already we’re hearing about House members who are jittery about a reconciliation bill, particularly those who represent Trump districts. The Problem Solvers Caucus has backed the bipartisan Senate proposal, but their thinking could be to just take that and run as well. Speaker Pelosi has remained strong on linking the two bills, and vowing not to pass either until the Senate passes both. But moderates are going to scream about that, and the thin margins in the House give them the leverage to force a shift.

Of course, progressives have that leverage too. And if moderates are left at the altar by nervous Republicans, progressives have a far better argument to say it’s time to stop waiting for bipartisan Godot and just execute the Biden agenda.