If the vocal "No" voters are the majority of the ones that vote this time, and at least 66.67% of them vote "No", it'll count as an automatic strike vote. But this does little to change things when Hoffa and the negotiating committee actually have the power to call the workers back from a strike whenever they decide to...
I am not an expert on what would happen if the national contract is voted down. It has never happened in my lifetime. The Central Supplement went down in 2013 the first time. That was renegotiated with a better Health and Welfare package and passed, but only for those who were transferring from the company plan into the union plan. The locals who were already under Team Care originally did not get the upgraded.
It is obvious that both negotiating parties do not want a strike..So expect them to go back to the table with an extension and go to Plan "B", the to Plan "C".
I still have worries about the International imposing the national because of poor voter turn-out. Hoffa is a lame duck president, I doubt that he would be running for another election at the age of near 80. He barely got in with the last one running against the TDU crew who early in the election lost their original presidential candidate on their ticket.
That is why the part time vote is so important, even though they do not turn in a ballot they could affect the ratification of this contract by lower the voter participation percentages just enough for the authorization of the 2/3 percentage majority "NO" votes that is required to vote it down. If by some miracle the membership can get to at least the 50 percent voter participation level, it will be a straight YES or NO vote.