There are close elections and then there are incredibly close elections. A state canvassing board in Iowa on Monday certified that Mariannette Miller-Meeks, a Republican, won an open congressional seat by a mere six votes.
After a recount that gave Ms. Miller-Meeks a lead of 196,964 to 196,958, the Democratic candidate, Rita Hart, signaled that she would challenge the outcome before a judicial panel, though her campaign did not immediately announce a challenge.
“Over the next few days, we will outline our next steps in this process to ensure that all Iowans’ voices are heard,’’ Ms. Hart’s campaign manager, Zach Meunier, said in a statement.
Ms. Hart has two days to challenge the certification under Iowa law, according to The Associated Press. A challenge would be heard before a tribunal consisting of Iowa’s chief justice and four state district judges. If the panel upheld Ms. Miller-Meeks’s victory, Ms. Hart could appeal to the U.S. House, where Democrats are in the majority. The A.P. said it would not call the race until all legal avenues are exhausted.
Ms. Miller-Meeks, a state senator making her fourth run for Congress, was certified the winner after recounts by the 24 counties of Iowa’s Second District. Her win, if it holds, would further erode Democrats’ House majority; Republicans flipped a net of at least nine seats this year that were held by Democrats.
The Hart campaign said the six-vote margin was the slimmest in any congressional race since 1984, when an Indiana race came down to just four votes.
Both candidates attended orientation in Washington for new members of Congress while the race — to replace a retiring Democrat, Representative Dave Loebsack — was undecided.
The Hart campaign held out hope that a challenge to the results might uncover valid ballots that were overlooked in the recount, which it requested on Nov. 12, when Ms. Miller-Meeks led by 47 votes.
“Under Iowa law, this recount process was designed to count ballots that had already been tallied, meaning that additional legal ballots may have yet to be counted,’’ the campaign said.
Although many polls of Iowa showed Joseph R. Biden Jr. and other Democrats competitive before the election, the party suffered broad losses in the state. President Trump carried it by 8.2 percentage points. And in Iowa’s First District, Representative Abby Finkenauer, a first-term Democrat, was unseated by Ashley Hinson, a Republican.