Routh was arrested in connection with what the FBI called an "attempted assassination" of Trump on Sunday, and an investigation has found Routh has a lengthy criminal record and was fixated on Russia's war in Ukraine. It was not clear what motivated Routh, if he was aiming his gun at the former president, nor if he fired a shot.
As authorities try to unravel the motive and details of the case, sources said investigators were looking at whether Routh was frustrated with Trump's position on Ukraine. Routh appears to have made recent social media posts critical of Trump and used social media to document his travel to Ukraine.
While it's not clear if any of Trump's Ukraine comments led to Sunday's incident, Trump and his running mate, Ohio Sen. JD Vance, have made comments about the Russia-Ukraine war and the United States' involvement in the conflict.
During the ABC News debate, Trump refused to answer if he wanted Ukraine to win its war against Russia when pressed twice.
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Instead, Trump said it would be in the country's best interest for the war to end.
"I think it's in the U.S. best interest to get this war finished and just get it done," Trump said. "All right. Negotiate a deal. Because we have to stop all of these human lives from being destroyed."
Trump has been critical of the U.S. involvement in Ukraine and the billions of dollars of aid the country provided to Ukraine's war effort. He has often calling out European allies for not contributing more resources to Ukraine.
The Biden administration has said that any victory Russia has in its war on Ukraine would encourage Putin to go after other Western-allied countries in Europe.
Trump has frequently touted that under his administration, there wouldn't have been a war with Russia to begin with, saying during the ABC News debate, "If I were president it would have never started. If I were president, Russia would have never, ever -- I know [Russian President Vladimir] Putin very well. He would have never -- and there was no threat of it either, by the way, for four years."
Trump has said repeatedly he would achieve a peace deal between Ukraine and Russia, but has not explicitly revealed a plan.
"I'll get the war with Ukraine and Russia ended. If I'm president-elect, I'll get it done before even becoming president," the former president said during the ABC News debate.
He celebrated his relationships with Putin and Ukraine President Volodmryr Zelenskyy while bashing President Joe Biden for his lack of communication with the world leaders.
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"I want to get the war settled. I know Zelenskyy very well and I know Putin very well. I have a good relationship," Trump said. "... They don't respect Biden. How would you respect him? Why? For what reason? He hasn't even made a phone call in two years to Putin. Hasn't spoken to anybody. They don't even try and get it. That is a war that's dying to be settled. I will get it settled before I even become president."
Vance has also been critical of the U.S. involvement in supporting Ukraine in its war with Russia, saying the country is wasting money and resources.
He has opposed more U.S. aid for Ukraine, saying in May, "I do not think that it is in America's interest to continue to fund an effectively never-ending war in Ukraine."
Vance has also voiced his skepticism since the earliest days of the conflict.
"I gotta be honest with you, I don't really care what happens to Ukraine one way or another," Vance said in February 2022, amid an explosion of bipartisan support for country in the immediate aftermath of Russia's invasion.
In a recent podcast interview, Vance laid out a potential approach a Trump administration would take in handling the Ukraine-Russia war, including creating a "demilitarized zone" in the parts of Ukraine that Russia has already taken over.
"So I think what this looks like is Trump sits down. He says to the Russians, the Ukrainians, the Europeans, 'you guys need to figure out what does a peaceful settlement look like,'" Vance said on the "Shawn Ryan Show" last week. "And what it probably looks like is something like the current line of demarcation between Russia and Ukraine. That becomes like a demilitarized zone. It's heavily fortified so the Russians don't invade again. Ukraine remains its independent sovereignty."
Vance also said the rest of Ukraine that Russia did not occupy would be a "sovereign state" and that Russia would get the "guarantee of "neutrality."
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"Russia gets the guarantee of neutrality from Ukraine. It doesn't join NATO, it doesn't join some of these sorts of allied institutions, and I think that's ultimately what this looks like."
Vance's suggested plan is the most specific policy outline the Trump campaign has offered regarding how it would handle the Ukraine-Russia war.
The plan Vance laid out is similar to what Putin put forward earlier this year, saying Ukraine must give up large amounts of its territory and renounce its ambitions to join NATO.