All 100 U.S. Senators voted for a symbolic constraint to keep President Clinton from invading Haiti without congressional consultation. This isn't likely to keep Clinton from sending in troops; it would just prevent him from calling the action "a war," a gambit employed by Presidents Nixon and Reagan, among others. Senate minority leader Bob Dole led the charge to ensure that Sunday's United Nations vote authorizing invasion doesn't make Clinton trigger-happy. Many Democrats went along only because the vote simply underscored the existing War Powers Act. Meanwhile, the Clinton Administration is hinting that invasion won't come till September -- if ever.