Ok, Now I am confused because I thought he vetoed this a couple of months ago too!
(WASHINGTON) – The following is a statement from Teamsters General President James P. Hoffa about the veto today of paycheck deception legislation by Missouri Gov. Jay Nixon (D) that would hamper the ability of unions to fully represent their membership in the state.

“Gov. Nixon has again stood up for everyday Missourians against corporate interests. Workers already have the ability to stop having dues withdrawn from their paycheck for political purposes. But by requiring public sector employees to opt-in annually, sponsors are looking to bog down the Teamsters and other unions in red tape.
https://teamster.org/news/2016/03/ho...employees-veto