If another continuing resolution to fund the government is passed Thursday without an immigration deal, Democrats will learn a hard lesson from history: If you’re in Congress and planning to shut down the government to score political or policy points, you might want to think again.

The idea that every shutdown has political “winners” and “losers” is an oversimplification; historically, the compromises that emerge from these standoffs have often allowed people on both sides to point at something that they could claim as at least a small victory. That said, the side that has consistently gotten the shorter end of the stick during shutdowns is the members of Congress who oppose the president. That’s bad news for 2018’s Democrats, who, if the historical trend holds, are unlikely to extract many concessions on immigration in the wake of their decision to force a government shutdown over the issue last month.

Indeed, the modern government shutdown was devised by the executive branch and was initially used as an instrument to put pressure on Congress. True shutdowns have only been possible since 1980, when Attorney General Benjamin Civiletti issued a legal opinion that funding gaps must lead to operational gaps as well. Before that, federal funding gaps existed only on paper; government continued to function on credit and simply paid costs retroactively. A tour through the history of government shutdowns before 2018 (specifically, the seven full-blown shutdowns in which government workers were furloughed; 11 other funding gaps didn’t lead to major service disruptions) shows how presidents have used them to their advantage.

The final scoreboard reads as follows: The president and his allies notched clear-cut wins in two shutdowns (1984 and 2013). They got the sweeter end of a mutually beneficial deal in three others (1990, 1995 and 1995-96). And the two sides arrived at a fairly equitable compromise in the remaining two examples (1981 and 1986). That means congressional agitators have never won a major shutdown standoff, and that should unsettle Democrats.