Pete Buttigieg Compares His Dark Horse Campaign with Trump's in 2015

Pete Buttigieg says while his odds to the win the White House might be similar to Donald Trump's a year out from election day ... he's going about getting there with a full 180.

The South Bend Mayor spoke to us Wednesday on "TMZ Live" after news broke that he's the leading Democratic candidate in Iowa, according to a new poll ... not to mention that his chances at going the distance are eerily similar to DT's from this time 4 years ago.

He weighs in on both, telling us the new poll reflects what he's been feeling on the ground ... a connection to voters and a groundswell that just can't be stopped.

As for the Trump comparison, he says the only thing he wants to share with 45 is the final destination. That said, he does admit there are similarities in how folks perceived their campaigns early on -- namely, they were seen as odd men out despite later success.

Then, we got into what could become a problem ... how PB plans to deal with religious voters -- especially in the South -- who may view the fact he's gay as a dealbreaker.