Godan verb with 'su' ending, Transitive verb
to demolish; to tear down; to pull down
クリントン陣営は、両州でオバマが取った白人票を取り崩そうと必死になった。The Clinton camp became desperate to eliminate the white votes Obama had got in both states. to draw on (one's savings, etc.) little by little; to break into (a reserve fund, etc.); to eat into
Also written 取崩す【とりくずす】