MUSCATINE, Iowa — Former Vice President Joseph R. Biden Jr. on Tuesday seized on comments by Senator Joni Ernst, Republican of Iowa, suggesting that the White House’s arguments at the impeachment trial could hurt his political fortunes.
At the impeachment trial on Monday, President Trump’s legal team spent time walking through Mr. Biden’s son Hunter’s work for Burisma, a Ukrainian energy company. Ms. Ernst suggested that the discussion could hurt Mr. Biden in the Iowa caucuses next Monday.
“I’m really interested to see how this discussion today informs and influences the Iowa caucus voters, those Democratic caucusgoers,” Ms. Ernst said. “Will they be supporting former Vice President Joe Biden at this point?”
At an event on Tuesday in Muscatine, Mr. Biden quoted Ms. Ernst’s comments.
“She spilled the beans,” Mr. Biden told the crowd. “She just came out and flat said it. You know, the whole impeachment trial for Trump is just a political hit job to try to smear me, because he is scared to death to run against me, and he has good reason to be concerned.”
He added: “You Iowa caucusgoers have a chance for a twofer here. You can ruin Donald Trump’s night by caucusing for me, and you can ruin Joni Ernst’s night as well.”
From the start of his campaign, Mr. Biden has argued that he is better positioned than any other candidate to defeat Mr. Trump in a general election. And as the impeachment proceedings have ramped up, he has been hammering the argument that he is the candidate Mr. Trump fears most.
Even before Ms. Ernst made her comments, Mr. Biden asked Iowans at an event in Ankeny on Saturday: “Can you think of any time when a sitting president has spent over $12 to $14 million so far and risked being impeached by getting a foreign leader to say something he wouldn’t say about me — not to deal with his opponent but to pick his opponent? I wonder why he’s afraid of me.”
Ms. Ernst, a first-term senator, is up for re-election in November in one of the most competitive races in the country: one crucial to Democrats’ hopes of retaking the Senate. And Theresa Greenfield, the Democratic Senatorial Campaign Committee’s preferred candidate in the primary to run against her, wasted no time capitalizing on Ms. Ernst’s remarks.
“Sounds like you’re focused on the wrong election, Senator,” she tweeted Monday evening alongside a call for donations.
On Tuesday morning, Ms. Greenfield added: “There’s a reason @joniernst is 3rd most unpopular Senator in the country. Instead of working to help Iowans, she’s doing the dirty work of Mitch McConnell in the Senate.”
Maggie Astor contributed reporting from Des Moines.