(NewsNation) — With a few weeks until the 2024 presidential election, border security has emerged as a central campaign issue. Both Democratic candidate Kamala Harris and Republican candidate Donald Trump are projecting tough stances on migration, making various claims about their records on border policy.

NewsNation fact-checked these claims, revealing a mix of truths, exaggerations, and falsehoods from both candidates.

Harris: ‘Most of the fentanyl in America comes from two cartels based in Mexico’

Fact check: True

Harris correctly stated that most fentanyl in America comes from two Mexican cartels, according to the Drug Enforcement Administration.

The DEA confirmed this, naming the Sinaloa and Jalisco New Generation Cartels as the primary sources of fentanyl entering the U.S., with most fentanyl seizures being at legal ports of entry.

Harris: ‘Last December I helped raise the rate of overtime pay for border agents’

Fact check: True

Harris accurately noted her support for increased overtime pay for border agents, as confirmed by the Consolidated Appropriations Act of 2023. The act devoted $125 million to address overtime pay for Customs and Border Protection agents. This funding aims to support agents as they manage increased workloads at the border.

Harris: ‘In the four years that Donald Trump was president, he did nothing to fix our broken immigration system’

Fact check: False

Harris’s claim that Trump “did nothing” to address immigration during his presidency was found to be false. Trump implemented several measures, including the “Remain in Mexico” policy and increased deportations, though these were often controversial.

Harris: ‘Donald Trump tanked [the border bill.] He picked up the phone and called some friends in Congress and said stop the bill’

Fact check: Misleading

Harris has pointed to Trump as being responsible for blocking a key border security bill. However, this claim is misleading, as many proposed bills failed due to bipartisan disagreements rather than due to direct actions by Trump alone.

Trump: ‘He’s allowed in my opinion…much more than 20 million people into our country’

Fact check: False

Trump’s claim that the Biden administration has allowed “much more than 20 million people” into the country is highly exaggerated, according to the House Committee on Homeland Security. The actual number of encounters at America’s borders is expected to reach about 10 million by the end of the fiscal year, including repeat crossings and deportations.

These encounters include repeat crossings and deportations, which means the actual number of unique individuals entering the country is much lower.

Trump: ‘That’s the lowest point in the recorded history of the border’

Fact check: Not entirely accurate

Trump’s assertion that illegal immigration reached its lowest point in history during his term is not entirely accurate. While there was a significant decline in crossings, FactCheck.org reports historical lows actually occurred in earlier decades, particularly in the early 2000s.

Trump: ‘We had the best numbers ever and we had them largely because of the wall’

Fact check: Not entirely accurate

The effectiveness of Trump’s border wall construction is partially true. While it did lead to decreases in crossings in specific areas, Department of Homeland Security reports indicate it was just one aspect of a larger security strategy.

Other measures, such as increased surveillance and policies like “Remain in Mexico,” also played critical roles in reducing crossings.

Trump: ‘They’re doing is protecting criminals which set loose illegal alien criminals rather than hand them over to ICE’

Fact check: False

Trump’s characterization of sanctuary cities as places that protect criminals rather than handing them over to Immigration and Customs Enforcement (ICE) is false, according to research from the American Immigration Council and Global Refugee. These cities often transfer individuals convicted of serious crimes to federal custody.