The smell of burning rubber is unmistakable during a U.S. Secret Service training exercise that will be critical to the security of President Joe Biden and former President Donald Trump during their upcoming party conventions.

Agents prepare for any threat, traveling at speeds approaching 90 miles an hour while navigating tight turns and stopping on a dime.

The Secret Service has also modeled a life-size town where agents train for an attack on a motorcade — one of many potential worst-case scenarios. Would-be attackers fire blank rounds from the cover of buildings on both sides of the street to simulate a real assault on a protectee. A counter-assault team jumps out of black SUVs to return fire and contain the situation.

“We have to train for the lone wolf gunman, all the way up to possibly state-sponsored terrorist attacks,” Secret Service Assistant to the Special Agent in Charge Shaun Miltier said.

The purpose is to have lethal force at the ready.

“We use speed, surprise and violence of action… to divert, suppress and neutralize that threat,” said Agent Kyle Kuhn with the Special Operations Division.

Republicans will host their convention from July 15-18 in Milwaukee. Democrats will hold theirs in Chicago from Aug. 19-22.

With the Republican convention just over a week away, the Secret Service and an army of federal, state and local agencies are working around the clock to prepare for any potential threat in a deeply divided country.

The security package in Milwaukee for the Republican National Convention is more than a year in the making. ABC News went inside a joint command center that will serve as a real-time coordination hub during the convention.

“We have many partner organizations at all levels of government that have been involved in this process, and we are continually monitoring information related to the event,” Secret Service Coordinator Audrey Gibson-Cicchino said. “So we are well prepared and have a plan in place to account for any situation that may arise.”

Federal and local law enforcement are coming together to protect the convention from the air, land and sea. Helicopters and airplanes are ready to patrol the sky, along with Secret Service drone pilots.

“If we get a report of a medical situation, we can use the drone to actually go over there, help identify the medical situation and direct our first responders to that area,” Secret Service drone pilot Matthew Malone said.

Milwaukee Police Department Harbor Patrol will also be on alert, guarding against any potential threats from Lake Michigan.

“We pretty much know the water like the back of our hand,” Milwaukee Police Chief Jeffrey Norman said. “And it’s important for us to understand those particular type[s] of sensitive areas and how to properly secure it.”

In Chicago, the Secret Service official overseeing security for the Democratic National Convention in August said he is confident in their plans and preparations.

“We’re not only here to ensure the safety of the attendees of the convention, but there’s almost 2.7 million residents of the city of Chicago that live and work here every day,” Secret Service Coordinator Jeff Burnside said.

Chicago police plan to put officers on bikes for crowd control, giving them an advantage in the event of civil unrest. The city’s top cop is also mindful not only of the threat of terror, but also how crowds themselves can be a security threat. The key, law enforcement leaders say, is balancing the right to protest with the need to maintain public safety.

“We want to protect those rights,” Chicago Police Superintendent Larry Snelling said. “But we’re also preparing and training for when things can’t be de-escalated, and they go off scale.”