The pilot reported that during the landing flare he experienced what he believed to be wind shear or a dust devil. Just before the airplane touched down it lifted about 20 to 40 feet when the wind suddenly shifted to a tailwind and the airplane stalled. The pilot stated that the right wing dropped and the airplane entered an approximate 45 to 60 degree angle of bank. The pilot corrected the bank angle and leveled the wings but failed to apply full power to completely recover from the stall. The airplane subsequently impacted the runway nose down, bounced, then settled to the runway. The firewall and fuselage were substantially damaged. The pilot reported no preimpact mechanical malfunction or failures with the airplane that would precluded normal operation. .