What you need to know:
- The campaign of McGrath, a former Marine fighter pilot, burned $88 million, the second costliest Senate run in US history.
- Fundraising is key to advertising campaigns and developing name recognition, but only goes so far in reversing long-entrenched political sentiment.
America's 2020 campaigns cost some $14 billion, a record sum showing that parties are increasingly willing to spend big on races to express visceral opposition to their rivals -- even when their chances are slim.
The enormous cost of this year's presidential and legislative elections is nearly double the cost of 2016's races, and more than triple those of 2000, according to the Center for Responsive Politics, a non-partisan research group that tracks money in politics.
The Democrats in particular lost some costly wagers this year.
South Carolina's incumbent Republican Senator Lindsey Graham easily beat his rival Jaime Harrison, who spent a record $108 million after donations from Democrats poured in from all over the country, according to Karl Evers-Hillstrom from the CPR.
"To all the liberals in California and New York, you wasted a lot of money," Graham said following his reelection.
To be fair, a number of billionaire donors gave to keep Graham afloat -- and, according to the CPR, the vast majority of his funds also came from out of state.
Amy McGrath in Kentucky also suffered a blow in her face-off with Republican Mitch McConnell, a senator since 1985 who Democrats desperately hoped to unseat given his unwillingness to compromise.
He recently triggered ire after pushing through the nomination of conservative judge Amy Coney Barrett to the Supreme Court just before the presidential vote.
The campaign of McGrath, a former Marine fighter pilot, burned $88 million, the second costliest Senate run in US history.
Republicans also lost some expensive investments: donors nationwide gathered some $10 million in a bid to thwart New York's Alexandria Ocasio-Cortez, the 31-year-old Democratic socialist who's amassed significant power in the House's left flank, to the disdain of conservative rivals.
Spending from her challenger, the 60-year-old ex-cop John Cummings, along with her own $17 million in fundraising made the race one of the most expensive House duels ever -- but the representative known as AOC breezed back into Congress by more than 38 points.
For campaign financing experts, pricey losses confirm that money isn't the only factor when it comes to winning elections, and can't change the political landscape overnight.
Michael Bloomberg, one of the richest people in the world, learned the hard way during the Democratic party that money alone can't buy him a spot in office: the former New York mayor spent $550 million in advertising -- a record for a campaign -- but gained little traction with voters.
Fundraising is key to advertising campaigns and developing name recognition, but only goes so far in reversing long-entrenched political sentiment.
"If you are in an ultra-red state, your chances of winning are pretty close to zero," said Evers-Hillstrom of the CPR. Yet donations keep pouring in.
For Michael Malbin, a political science professor at the State University of New York, the stark polarization of the Donald Trump years has played a large role in motivating donors.
Anger and rejection of Trumpism on one side, an indictment of "Socialism" on the other -- such factors are "strong motivators" to donate, Malbin said.
It's unsurprising, then, that the largest sums are concentrated on candidates like McConnell, Graham and Ocasio-Cortez, politicians who incite constituent's passions.
But while thousands of donors contribute to high-profile battles, "90 percent of the races in this country are underfunded on one side or the other," Malbin said.
"Money is going... to the candidates who have so much money they don't know what to do with it."
The ease of donating online has also changed the game, since the Democrats launched the online platform ActBlue in 2004.
"It's become incredibly easy, it's the Amazon of politics," Malbin said. "All you have to do is click."
If one thing is clear, it's that campaign spending is unlikely to fall anytime soon in a country with few limits on financing elections.
"If we continue to be as polarised as we are, we can probably expect a lot of money to be spent," said Evers-Hillstrom.