Before the heavens opened up this morning and unleashed a downpour on the northwest Bronx, State Senator Adriano Espaillat stood at the foot of the elevateed Kingsbridge Road 4 train station handing out flyers.

“Stete Senator Espaillat for Congress, June 26,” he repeated, greeting commuters in English and Spanish as they whipped by on their way downtown. His “campaign mobile,” a wide, heavy truck with plastic-wrapped seats strapped into the back bed, was parked at the corner of Jerome Avenue and Kingsbridge Road, blasting funk music.

Espaillat, who is considered the biggest threat to unseat incumbent Congressman Charlie Rangel in the race for the newly constituted 13th Congressional District, which stretches from Harlen through upper Manhattan and into the northwest Bronx, rocked back and forth, waiting for the next potential voter.

“It’s like winter out here,” he said of the cool morning air.

Espaillat said he was planning to get breakfast at New Capitol Diner across the street before meeting up with Councilman Oliver Koppell to receive the longtime Bronx politician’s public endorsement.

With a little more than a month to go before the June 26 primary, the race is beginning to take shape, with Bronx elected officials (and former elected officials) falling behind either Rangel or Espaillat.

Bronx Borough President Ruben Diaz Jr. and his dad, State Senator Ruben Diaz Sr. are backing Rangel, along with Bronx Democratic Party Chairman Carl Heastie, who says he’s simply supporting all incumbents. Meanwhile, in addition to Koppell, who represents much of the Bronx portion of the new congressional district, State Senator Gustavo Rivera is campaigning hard for Espaillat, setting up house parties and asking his supporters to vote for his colleague inAlbany. Diaz Jr.’s predecessors as borough president, Adolfo Carrion and Freddy Ferrer, are supporting Espaillat.

Conchita Cruz, Rivera’s chief of staff, said the Bronx could be a key swing area because Espaillat has strong support in Washington Heights, while Rangel’s base is in Harlem. East Harlem pols, including two that also represent parts of the Bronx — Councilwoman Melissa Mark Viverito and State Senator Jose M. Serrano — endorsed Rangel over the weekend. (The Politicker picked up on our report about Espaillat receiving support from an anti-incumbent Super PAC and saying, “I’m not going to say no” to that support).  But neither Espaillat or Rangel has campaigned in the Bronx neighborhoods now in the district, meaning those voters could be up for grabs.

Espaillat said his main goal is to get out the vote here in the Bronx — that’s why he’s pounding home the primary date (June 26!) every time he meets voters. He believes a larger turnout benefits him. Unfortunately, he said, Bronx voters, especially in areas like Norwood, are under-served in terms of polling sites. That’s not something that can be fixed a month away from the primary.