When former President Donald Trump walked into the headquarters of the International Brotherhood of Teamsters on Wednesday, he became the first Republican presidential candidate to have a real shot at the union’s endorsement in more than 30 years.

The last time that the Teamsters union, one of the nation’s most powerful labor unions, endorsed a Republican candidate for president was in 1988 when it backed George H.W. Bush. Since then, it has endorsed the Democratic nominee in eight consecutive presidential elections.