• If the speed limit was 100 miles an hour, people would drive slower?
• If it was legal to shoot people, gun violence would decrease?
• If kidnapping was legal, there would be fewer kidnappings?
• If shoplifting was legal, fewer people would shoplift?
• If bank robbery was legal, fewer banks would get robbed?
• If domestic abuse was legal, domestic abuse would decrease?
• If child abuse was legal, child abuse would decrease?
• If racial discrimination was legal, there would be less racism?
• If slavery was legal, nobody would own slaves?
• If hate crimes were legal, the number of hate crimes would drop?

No?

Then why do you believe that keeping abortion legal will reduce the number of abortions?