한국계 홍, 22%p 우세였으나 패배…‘미 여론조사’ 신뢰 무너져

A recent Wisconsin Democratic gubernatorial primary held on November 5 saw Frances Hong, a Korean-American lawmaker, lose despite an expected victory, raising questions about the reliability of election polls. With President Donald Trump recently criticizing unfavorable polling results as "fake news," political trust in polls could be further eroded by the discrepancy between opinion polls and actual results in the midwestern primary.

Opinion poll experts suggest that Hong's strong support from younger and progressive voters might have been overrepresented in the polls. These voters, who showed more enthusiasm for early voting, may have actively participated in surveys more than others. State Navigate's Chaize Note, which conducted polls prior to the election, noted the "non-response bias" in November 12th polls, where Hong's supporters were more likely to respond than others.

Adjusting for differing political leanings among non-respondents could rectify some errors, but it's challenging to correct them entirely based on age or demographic characteristics. State Navigate corrected for younger voters' lower participation in a poll conducted between the 3rd and 6th of November, showing Hong leading by 22 percentage points.

However, polls conducted between the 8th and 11th also indicated Hong leading by 22 percentage points. Wisconsin's election system, which doesn't require voter registration by party, complicates polling by making it difficult to predict the participation of Democratic and Republican-leaning voters. The New York Times suggests the pollsters may have underestimated the proportion of Republican-leaning voters, noting that "Republicans who voted would have overwhelmingly opposed Hong."

Opinion poll analysts agree that the main issue is not that Hong's support was overestimated but rather that the late surge for Crawley wasn't captured. Charles Franklin Market, a responsible for Market Research at Columbia University, explained to the Washington Post that they had Hong at 38% while he ended up with around 39.5%.

While Hong's final vote percentage was close to the polls, Crawley's support increased from 7% to 39% in later polls and real voting results. The race remained volatile until the final polling day. Crawley suspended her campaign on August 8th, returned just three weeks later, and lost several key supporters, including Democratic Governor Tony Evans and former Governor Mandela Barnes.

Market Research's final poll showed 34% of Democratic voters still undecided on their candidate. This mirrors the closely contested Wisconsin Senate race a week prior, where progressive candidate Anwar El-Sayed led in polls but narrowly won with just a one-point margin. The New York Times analyzed these two midwestern polling errors, suggesting that the difference between passionate support and actual voter turnout could be a key challenge for future election polling.