Yet, ironically, the impeachment effort and the Republican counterattack against it have largely accomplished Trump’s goal. By keeping Hunter Biden’s business dealings in Ukraine in the news, they have turned them into a rough analogue to Hillary Clinton’s missing emails in 2016—a pseudo-scandal that undermines a leading Democratic candidate’s reputation for honesty. The Trump campaign and the Republican National Committee last fall launched a $10 million advertising blitz aimed at convincing Americans that Joe Biden’s behavior toward Ukraine was corrupt. After Trump’s lawyers devoted much of their energy in the Senate impeachment trial to demanding that Biden be investigated for corruption, Republican Senator John Barrasso of Wyoming crowed that the attacks would be politically “harmful” to the former vice president “in November if he’s the nominee and I think even in terms of getting the nomination.”

Barrasso was right. Although Trump and his allies have proved no wrongdoing, the Ukraine story, according to an October Investor’s Business Daily poll, made 23 percent of Americans less likely to vote for Biden, and only 8 percent more likely to vote for him. A Hill-HarrisX poll that same month found that 54 percent of independents—and even 40 percent of Democrats—considered “Hunter Biden’s business dealings in Ukraine an important campaign issue that should be discussed.”

Biden’s extremely defensive response to the story has made matters worse. When a Fox News reporter asked the former vice president about his son’s work in Ukraine in September, Biden lectured, “Ask the right question.” In December, after Biden called an Iowa man a “damn liar” for raising the issue, Politico noted, “Biden has two methods of responding to questions about his son’s controversial business dealings in Ukraine: denial and anger. But so far, Biden doesn’t have a clear and cogent message—and Iowa voters are starting to take notice.” On caucus day itself, when NBC’s Savannah Guthrie asked about Hunter’s work in Ukraine, Biden snapped, “You don’t know what you’re talking about.”

Biden has plenty of other weaknesses. But the Ukraine story is likely one reason that, according to a January Quinnipiac poll, he trails Bernie Sanders by nine points on the question of which Democratic presidential candidate is most honest. Since entering the race, Biden has generally performed better than his leading rivals in head-to-head polls against Donald Trump. But there’s evidence that over the course of last year, the pre-impeachment advantage Biden enjoyed in key swing states eroded.

Read: What Joe Biden can’t bring himself to say

Amazingly, impeachment appears to have hurt Biden more than Trump. Since House Speaker Nancy Pelosi initiated the impeachment inquiry on September 24, Trump’s approval rating has generally risen. It stood at 40 percent in the first Gallup poll after Pelosi’s announcement. In Gallup’s latest survey, Trump stands at 49 percent. According to RealClearPolitics’ polling average, Trump’s rating dropped a bit during the first month of the impeachment fight but has climbed ever since, and is now almost 45 percent—nearly as high as it has been during his entire presidency. As Aaron Blake has pointed out in The Washington Post, Trump has also seen a spike in the intensity of his support, while the intensity of public opposition has declined. Since late October, according to a recent Washington Post–ABC News poll, the percentage of Americans who strongly approve of Trump’s job performance has jumped five points, while the percentage who strongly disapprove has fallen eight points.