Republican leaders from around the country have taken the stage in Milwaukee this week, praising their presidential pick Donald Trump and bashing President Joe Biden.

Several speakers hammered on the economy as a big mark against Biden's record, encouraging voters to remember how much gas prices have changed in the last few years.

Lara Trump Tuesday night said, "gas hit a low of $1.87 a gallon," under her father-in-law's presidency. "As I speak here to tonight, many of our fellow Americans don't know how they'll pay for their next trip to the grocery store," she continued.

Despite some economic successes under the Biden administration, many voters still think Trump handled the economy better. RNC speakers seem to be pointing to gas prices as evidence.

Experts say that presidents have little control over gas prices, though it frequently is used as partisan slander.

"Perceptions of gas prices and the president's role in them is something that's really filtered through political partisanship," Charles Franklin, the director at the Marquette Law School Poll, told USA TODAY Wednesday. "Most parties use them when prices are up and when the other party is in the White House."

Here is what to know about gas prices during the candidates' tenures in office:

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Historical look at gas prices, according to AAA

Why gas is a gauge for other economic issues

Gas prices, though often at the whim of the global market, are a relatable issue for voters, Franklin said.

"They are a good and tangible sign of cost of living," he said. "You drive past a gas station, you see the price. You fill up your tank, pay the price...and so it's one of those things about economics where people do see it constantly and feel it in their purchases."

Despite its popularity as a talking point, Franklin said he has not found a correlation between gas prices and presidential approval ratings.

Still, Franklin said we don't forget those former low prices easily, even though wages have risen quicker than the rate of inflation.

"It takes a long time for us to reset what we think is a normal price for things, and real income catches up faster than the psychological perception about what's a high price."

Biden released oil from emergency reserve as prices spiked

Climbing gas prices throughout 2021 led Biden to dip into the emergency oil reserves, but it did little to stop growing prices at the gas pump.

In February 2022, Russia invaded Ukraine, impacting global supply and raising prices at the pump. In the month after the invasion, prices jumped up nearly $1 per gallon in the U.S. on average. In an effort to bring those prices down, Biden ordered the release of up to 180 million barrels of oil from the country's national emergency reserve, the largest release in the reserve's history.

In the following months, Biden called on Congress and state governments to implement a gas tax holiday for three months, but it never came to fruition.

Franklin said it would be difficult for Biden to use these moves as political rebuttal.

"Maybe at the margins that helped to hold prices down," he said. "That is something that maybe shows up to economists analyzing the macro economy. It's not likely something that people have any personal experience with or appreciation of."

Gas prices hit historic lows during pandemic-halted travel under Trump

Throughout the end of 2018, gas prices fell after the Organization of the Petroleum Exporting Countries contributed to oversupply of the market.

Again in 2020, as travel around the world came to a screeching halt due to the COVID19 pandemic, prices fell. Simultaneously, major suppliers were having a price feud as fear of recessions loomed, and many states saw prices dip below $2 per gallon.

Franklin said it would have been odd for Trump to take credit for those low prices at the time, but it isn't surprising it has come up as a talking point now, especially as people appear to remember the economy more favorably under his administration.

"Now here in the past tense, running for election again, it's certainly to be expected that the Trump campaign would point back to the low points of gas prices and say, 'they were lower when I was in office, especially in 2020,'" Franklin said.

Contributing: Phillip M. Bailey, Michael Collins, Sara Chernikoff, Mike Snider, Nathan Bomey, Jazmin Goodwin, Joey Garrison, Rachel Barber