president donald trump plan make easy small businesses band together buy stripped-down health insurance plan could violate federal law govern employee benefit plan almost certainly challenge court legal experts say trump sign executive order thursday aim let small businesses join nationwide associations purpose buy large-group health plan subject coverage requirements affordable care act commonly know obamacare industry experts say trump order could ultimately enable associations purchase insurance state few regulations would undermine obamacare former democratic president barack obama signature healthcare law republicans fail repeal several healthcare employment law experts say trump plan move forward state could argue federal government overstep authority violation u.s. employee retirement income security act erisa law govern large-group plan thursday order trump ask department labor propose rule would allow employers participate association health plan legal experts say lawsuits might bring regulations issue dania palanker assistant research professor georgetown university center health insurance reform say erisa grant state right regulate association health plan attorneys general could argue federal government overreach trump administration wind allow associations buy health coverage across border comply single state regulations attempt allow sale association plan small group across state line open legal scrutiny whether violate erisa undermine state authority say palanker white house official say departments draft rule way minimize litigation risk department labor review erisa course follow president direction order official say number state attorneys general democratic-leaning state say thursday would fight efforts weaken obamacare extend health insurance 20 million americans republicans call intrusive ineffective come surprise california prepare fight court protect affordable healthcare people say xavier becerra state democratic attorney general legal experts say state may argue associations form purpose buy insurance employers erisa although erisa allow associations qualify employers manage large-group plan federal regulators generally require members associations high degree common interest beyond buy insurance say allison hoffman professor university pennsylvania school law trump order ask secretary labor enforce erisa consider expand common-interest requirements permit broad participation association health plan short-term plan idea expand association health plan across state line long champion republican u.s. senator rand paul make key plank proposal repeal replace obamacare kentucky republican trump side president sign executive order paul proposal say erisa restrictive definition associations law need amend thursday order also ask labor treasury health human service departments look expand participation cheap bare-bones short-term limited-duration insurance plan subject aca timothy jost professor washington lee university school law say move would face few legal hurdle expansion association health plan current three-month limitation use plan rule adopt obama administration last year trump administration could roll back normal rulemaking process plan typically market individuals job gap coverage much cheap aca plan cover less exclude pre-existing condition trump healthcare order could run afoul retirement plan law