EVELYN SALYER IS THE KIND OF VOTER REPUBLICANS DESPERATELY NEED TO HANG ONTO THIS FALL. IN 2004, HER VOTE HELPED PUSH A REPUBLICAN HOUSE MEMBER TOWARD A NARROW REELECTION WIN IN THIS NORTHERN INDIANA DISTRICT. NOW, WITH A NEW ELECTION JUST DAYS AWAY, SHE HASN''''T MADE UP HER MIND. THE CANDIDATES ARE THE SAME TWO MEN WHO RAN LAST TIME. THEIR BATTLE FOR BLUE-COLLAR VOTERS IS LUG-WRENCH TIGHT. AND MS. SALYER CITES ECONOMIC CONCERNS AMONG THE MIX OF ISSUES THAT MAKE HER RELUCTANT TO COMMI