We don't know whether the government will shut down yet (though it's looking more likely by the hour), but lawmakers are already playing the blame game.

Both sides are pointing the finger at each other, which is a reflection of how both sides could get the blame for the first government shutdown in more than four years.

Congress is doing it, so you can do it, too. Here's how to blame the party you're against for a government shutdown. 

If you want to blame the Democrats, say:

Democrats are taking a stand on immigration on a totally unrelated spending bill: If the government shuts down, it's likely that more Democrats will have voted against a spending bill than Republicans. And that gives Republicans an opening to argue that Democrats shut down the government. “The point is: Who's not funding the government, and why?” said Josh Holmes, a former top aide to Senate Majority Leader Mitch McConnell (R-Ky.).

Not only that, most Democrats who oppose the spending bill oppose it because it doesn't protect young immigrants in the country illegally, known as “dreamers.” But dreamer protections don't expire until March.

Holmes says what's happening today is almost exactly like what happened during the 2013 shutdown, when conservative Republicans refused to vote for a spending bill that funded Obamacare. The government shut down for 16 days, and polls showed a majority of Americans blamed Republicans for that.

“You take the party label off and watch how that's played out,” Holmes said. “It's never been good for the party that's blocking the funding for reasons irrelevant to the funding.”

Democrats aren't willing to compromise with Trump because he's Trump: Democrats really doubled down on getting a deal for dreamers after a fateful White House meeting last week at which Trump asked why the United States keeps taking immigrants from “shithole countries” such as Haiti, El Salvador and African nations.

Democratic opposition hardened, opening the door for Trump to argue that Democrats are obstructing his agenda (and stepping on his tax success from last month).

“That is not a good subject for them, the tax cuts,” Trump said in Pennsylvania on Thursday.

Democrats' hard line on immigration comes at the expense of health insurance for low-income kids: At the last minute, GOP leaders threw some bait for skeptical Democrats: Vote to keep the government open and we'll also extend the Children's Health Insurance Program for six more years. Now those same GOP leaders are framing the spending debate as: Democrats who vote against this spending bill are voting against CHIP.

Democrats say that's misleading. The program expired under Republicans' watch in September. Why should they be to blame for this?

Speaking of ...

If you want to blame the Republicans, say:

They literally control all of Washington. How can the shutdown not be their fault? The whole reason Democrats have leverage to demand protections for dreamers is because Republicans need their votes to keep the government open. A chunk of conservative Republicans have voted against spending bills for the past several years and could do the same again.

“They control all the levers of power, and they could have dealt with this months ago, but they keep on just kicking the can down the road because they can't get their own act together,” said Jim Manley, a former top Senate Democratic aide.

A Quinnipiac University poll released Thursday found Americans split the blame between both parties in Congress and Trump. But when you lump Trump in with Republicans in Congress, a majority (53 percent) would blame members of the Republican Party.

House Republicans are voting on a bill that can't pass the Senate: Republicans fire back that even if they could pass a spending bill in the House with their own members, Senate Democrats would just block it by requiring 60 votes, which is about 10 more than Republicans have.

That's probably true. But that misses the point, Senate Democrats say. Republicans knew all along that Senate Democrats have leverage to block the bill. So why weren't Democrats part of the negotiations on this short-term spending bill? And how can they be expected to vote for something they weren't consulted on?  

“As typical of this Republican majority, it was done with zero negotiations with Democrats,” Senate Minority Leader Charles E. Schumer (D-N.Y.) said Thursday.

Trump doesn't know what he wants: He's contradicted his party's leaders so many times on immigration and funding for CHIP that it almost seems Trump wants a shutdown.

The president's indecision has made it impossible for Republicans to pick a strategy and stick with it, which then muddies the whole negotiating process.  “We don’t have a reliable partner at the White House to negotiate with,” Sen. Lindsey O. Graham (R-S.C.) said Thursday after Trump tweeted that.

If you're not sure whom to blame yet …

Just watch what happens. Both sides have a reasonable case to make. It will probably all come down to messaging.

“It will likely depend on what is the primary issue that causes the shutdown and who is more successful communicating,” GOP strategist Alex Conant said in an email to The Fix.

How that blame translates at the polls later this year is still an open question. Conant says a shutdown will probably fuel anti-Washington sentiment, which in turn will boost challengers to sitting members of Congress. That means different things for different Republicans.

In the House, Republicans are trying to hold on to 23 districts that voted for Hillary Clinton in 2016, so these House GOP lawmakers could find themselves on the defensive if the government shuts down.

But in the Senate, Republicans are trying to kick out at least 10 Senate Democrats running for reelection in Trump states. A shutdown under Republicans' watch could help those GOP challengers.

In short: If the government does shut down, who takes the blame will be up for grabs, but both sides have legitimate points to make. And now you've got a cheat sheet to argue whatever side you want to pick.