WASHINGTON \u2014 After the courts deprived him of his census \u2014 at least the version he wanted \u2014 President Donald Trump promised Thursday that he would fight like heck to let Americans know how many residents of the country are citizens and how many aren't."We are not backing down," he declared under a foreboding sky in the White House's Rose Garden as he blamed "unfriendly" federal judges and "left-wing" opponents for a legal tangle that forced him to abandon plans to include a citizenship question on the questionnaire the Commerce Department uses in its decennial population count.Then he announced an executive order directing federal agencies to share with the Commerce Department any information that would help sort people into citizenship-status categories \u2014 a process that already occurs in significant measure \u2014 to obtain what will perhaps be a slightly more detailed version of a picture that has long since been painted.\u201cIt\u2019s really just a repackaging of what the government already does,\u201d Vanita Gupta, president and CEO of the Leadership Conference Education Fund.It was played up as a major defeat for Trump by Gupta and other critics of the president, who noted that there had been nothing preventing him from issuing the order before a series of adverse court rulings pushed him up against a deadline to start printing the questionnaire so that it could be distributed in time."Trump's attempt to weaponize the census ends not with a bang but a whimper," Dale Ho, director of the ACLU's Voting Rights Project, said in a statement.But the fight isn't over \u2014 a reality that Attorney General William Barr nodded to in remarks delivered right after Trump spoke.The latest dustup was merely a skirmish in the larger war over using citizenship status to help determine which party controls the White House and the House in the future, as well as how federal money is distributed."That information will be used for countless purposes," Barr said. "For example, there is a current dispute over whether illegal aliens can be included for apportionment purposes. ... We will be studying this issue."For most Americans, "apportionment" is a pretty meaningless word. But in politics, it's freighted with power.Every 10 years, after the census is taken, the 435 seats in the House of Representatives are reapportioned based on each state's share of the national population. The allotments are based on a formula that assigns the most seats to the states with the largest number of people and the fewest seats to those with the least number of people \u2014 with each state getting at least one representative in the House.California, the most populous state in the country, has 53 House seats. If there were fewer people in California \u2014 or a large proportion of its population were not counted \u2014 it might lose representation to another state.It doesn't just matter for the House. Because the number of votes each state gets in the electoral college is based on its congressional representation \u2014 one elector per House member plus one for each senator \u2014 a change in apportionment could also affect presidential elections.Additionally, many federal programs distribute funds to states or local governments through population-related formulas.All of that is to say, it matters how many people are counted in the census \u2014 and where.Trump's opponents in the census fight say there are at least two ways in which he's been threatening to significantly tilt political power. The first is the imposition of a chilling effect that makes it less likely that non-citizens will respond to census questions \u2014 not to mention citizens who worry that they might be misidentified or who become mistrustful of government.On a longer horizon, the legal action Barr referred to could result in a determination that undocumented immigrants cannot be counted for purposes of apportionment. It's the latest tangle over a question \u2014 who gets counted, and how \u2014 that has been perhaps the most divisive political issue in American history.When the Constitution was written, the same "enumeration" clause that established the census and apportionment rules also mandated that slaves would each be counted as three-fifths of a person \u2014 the notorious "three-fifths" compromise that allowed slave-holding states to have power in the federal government while denying liberty and rights to millions of slaves.In a case that is still moving through the courts, Rep. Mo Brooks, R-Ala., and the state of Alabama have sued the Commerce Department to try to block the counting of undocumented immigrants for purposes of apportionment. The Trump administration sought and failed to have the case dismissed on the grounds that neither Brooks nor the state had standing to sue, meaning that it will move forward.But when Barr raised the issue Thursday, he suggested that the information the census obtains could used for the purpose of excluding undocumented immigrants from the apportionment figures \u2014 a point that could suggest Justice isn't that invested in continuing to fight Brooks.For now \u2014 and with future court cases more likely to affect the 2030 census than the 2020 round \u2014 Trump is casting himself as an agent of transparency, and his political opponents as impediments to the count."Far left Democrats in our country are determined to conceal the number of illegal aliens in our midst," he said Thursday.Yet it is Trump whose party will be most pleased if undocumented immigrants aren't counted in the future, and Democratic-leaning constituencies who stand to lose if they aren't \u2014 which is why they celebrated Thursday's capitulation on the citizenship question as a big loss for the president who'd pushed so hard for its inclusion.Jonathan Allen is a Washington-based national political reporter for NBC News who focuses on the presidency.