That all elections shall be free and open; and no power, civil or military, shall at any time interfere to prevent the free exercise of the right of suffrage.

Source: Const. of 1875, Art. II, § 9.

  (1964) In appeal from action to contest county school superintendent election, dicta contained in opinion stated that if § 167.020 were construed to prohibit write-in candidates it might be violative of this section and unconstitutional. Kasten v. Guth (Mo.), 375 S.W.2d 110.

  (1974) Statute requiring voter to make his ballot preference known to judge in primary election held not to violate this provision. State ex rel. McClellan v. Kirkpatrick (Mo.), 504 S.W.2d 83.