A new set of TRICO blades (www.tricoproducts.com
) is what I would use.
If the arms have been bent, replace them too.
It that doesn't work it's your windshield that's the problem. Wipe it down with lacquer thinner to make sure any wax or oil is removed. It also could be sandblasted, acid etched, scratched or covered with fine paint overspray. Polishing it may work if it's etched but pitting/scratching will require replacement.