BOSTON (AP) — Democratic state attorneys general on Friday will seek to block PresidentDonald Trump's proposal for a sweeping overhaul of U.S. elections in a case that tests a constitutional bedrock — the separation of powers. The top law enforcement officials from 19 states fileda federal lawsuitafter the Republican president signedthe executive orderin March, arguing that its provisions would step on states' power to set their own election rules and that the executive branch had no such authority. In a filing supporting that argument, a bipartisan group of former secretaries of state said Trump's directive would upend the system established by the Constitution's Elections Clause, which gives states and Congress control over how elections are run. They said the order seeks to "unilaterally coronate the President as the country's chief election policymaker and administrator." If the court does not halt the order, they argued, "the snowball of executive overreach will grow swiftly and exponentially." Trump'selection directivewas part of a flurry ofexecutive ordershe has issued in the opening months of his second term, many of which have drawnswift legal challenges. It follows years of himfalsely claimingthathis lossto Democrat Joe Biden in the 2020 presidential election was due to widespread fraud andan election yearin which he and other Republicans promoted the notion thatlarge numbers of noncitizensthreatened the integrity of U.S. elections. In fact, voting by noncitizensis rareand, when caught, can lead to felony charges and deportation. Trump's executive order would require voters to show proof of U.S. citizenship when registering to vote in federal elections, prohibit mail or absentee ballots from being counted if they are received after Election Day, set new rules for voting equipment and prohibit non-U.S. citizens from being able to donate in certain elections. It also would condition federal election grant funding on states adhering to the strict ballot deadline. The hearing Friday in U.S. District Court in Boston comes in one of three lawsuits filed against the executive order. One is fromOregon and Washington, where elections are conducted almost entirely by mail and ballots received after Election Day are counted as long as they are postmarked by then. The provision that would create a proof-of-citizenship requirement for federal elections already has been halted ina lawsuitfiled by voting and civil rights groups and national Democratic organizations. In that case, filed in federal court in the District of Columbia, the judge said the president's attempt to use a federal agency to enact a proof-of-citizenship requirement for voting usurped the power of states and Congress, which at the time was considering legislation that would do just that. That bill, called the SAVE Act,passed the U.S. Housebut faces an uncertain future in the Senate. Trump's executive order said its intent was to ensure "free, fair and honest elections unmarred by fraud, errors, or suspicion." The Justice Department, in arguing against the motion by the attorneys general for a preliminary injunction, said the president is within his rights to direct agencies to carry out federal voting laws. The order tasks the U.S. Election Assistance Commission with updating the federal voter registration form to require people to submit documentation proving they are U.S. citizens. Similar provisions enacted previously in a handful of states have raised concerns about disenfranchising otherwise eligible voters who can't readily access those documents. That includesmarried women, who would need both a birth certificate and a marriage license if they had changed their last name. A state proof-of-citizenship law enacted in Kansas more than a decade agoblocked the registrationsof 31,000 people later found to be eligible to vote. The two sides will argue over whether the president has the authority to direct the election commission, which was created by Congress as an independent agency after the Florida ballot debacle during the 2000 presidential election. In its filing, the Justice Department said Trump's executive order falls within his authority to direct officials "to carry out their statutory duties," adding that "the only potential voters it disenfranchises are noncitizens who are ineligible to vote anyway."