Republicans have discovered their tax law contains a mistake and are hoping Democrats will help them fix it. But if the narrative of "one party passed a giant law and now wants to change it" sounds familiar, Republicans are insisting this is different from when they wouldn't help fix the Democrats' Affordable Care Act.

Between the lines: This is a great indicator of why Congress struggles to get anything done — because now the precedent has been set for one party to refuse to fix problems with the other party's laws. And for what it's worth, some Democrats are also denying the parallel — because, of course, they say their ACA process was much more inclusive than the GOP's tax one.

Setting the scene: The tax law has a provision that's being referred to as the "grain glitch" that hurts some farmers. That's got some Republicans in a panic, and as they rightly point out, Democrats represent farmers too. (Reminder: Every state has a Medicaid program and people who get insurance on the individual market.)

The bottom line here is that to fix their mistake, Republicans need at least some Democrats to vote with them to do so.

I asked a lot of Republicans what Democrats seem likely to do and whether this was reminiscent at all of Republicans not wanting to improve the ACA. Their answers were all over the map — everything from "that was different" to "we should fix both" to memory loss.

On whether Republicans should have fixed the ACA:

Sen. Jeff Flake: "I don’t know, I don’t remember what we didn’t want to fix. It’s been too long I guess.”

"I don’t know, I don’t remember what we didn’t want to fix. It’s been too long I guess.” Sen. John Kennedy: “I wasn’t here then. I can tell you, if somebody pointed out something in legislation that I opposed that was going to hurt somebody unfairly, I would cooperate with them."

“I wasn’t here then. I can tell you, if somebody pointed out something in legislation that I opposed that was going to hurt somebody unfairly, I would cooperate with them." Sen. Jerry Moran: "I think in both instances, it’s wrong not to fix legislation that has flaws, and Republicans should cooperate on legislation that is supported largely broadly by Democrats and Democrats should help us fix problems. This is about our constituents."

On what's the difference:

Sen. Joni Ernst: "Republicans acknowledge [the tax law is] not working the way it was originally intended. Democrats have never acknowledged that Obamacare failed.”

"Republicans acknowledge [the tax law is] not working the way it was originally intended. Democrats have never acknowledged that Obamacare failed.” Sen. John Thune: "Most of the ACA stuff, we kind of wanted to undo the whole thing. This is a technical, unintended consequence that has broad ramifications for both Democrats and Republicans."

"Most of the ACA stuff, we kind of wanted to undo the whole thing. This is a technical, unintended consequence that has broad ramifications for both Democrats and Republicans." Sen. Thom Tillis: "Health care, in my opinion, there’s a universal problem. When you’re talking about ag policy, there’s a number of states that are going to be disproportionately hit."

"Health care, in my opinion, there’s a universal problem. When you’re talking about ag policy, there’s a number of states that are going to be disproportionately hit." Sen. Rob Portman: "There’s no ideology here. It’s an inadvertent problem that needs to be fixed. So I would think people will want to do that.”

On why Democrats should help fix the "grain glitch":

Sen. Pat Roberts: "That should be a bipartisan concern about what’s going on. I don’t know why they would want to hold it up other than politics.”

"That should be a bipartisan concern about what’s going on. I don’t know why they would want to hold it up other than politics.” Thune: "This is not a Republican or Democrat problem, it’s a problem that affects farm country, and if we don’t fix it, it’s going to create a lot of disruption.”

"This is not a Republican or Democrat problem, it’s a problem that affects farm country, and if we don’t fix it, it’s going to create a lot of disruption.” Sen. Rob Portman: "A lot of Democrats from rural states will want to fix it because it’s going to hurt their constituents."

"A lot of Democrats from rural states will want to fix it because it’s going to hurt their constituents." Sen. Chuck Grassley: "Surely Democrats have to understand that when you make a mistake like that, it ought to be fixed without bargaining with them on something else."

To be fair, some Democrats also disagreed with the comparison, albeit for totally different reasons:

Sen. Tim Kaine: "The difference is, their thumbprints were all over the ACA. They got 160 amendments to it. They made a strategic decision on the floor to vote against it, but they didn’t have process arguments ... So no, I don’t think it’s an analogous argument at all.”

#notalldemocrats:

Sen. Joe Manchin: “I’m willing to fix anything that needs to be fixed. I was here when everyone stonewalled everything. I watched what happened to the Affordable Care Act ... It’s not like it’s payback time. I didn’t come here for that."

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