If President Donald Trump's approval rating doesn't improve it could spell trouble for Republicans running in 2018, according to FiveThirtyEight.
Polls from Rasmussen Reports and Politico/Morning Consult show most Americans are equally divided over Trump, but slightly more approve than disapprove, while Gallup shows a more negative view of his brief time in office.
Usually, according to FiveThirtyEight, new presidents receive a grace period early in their terms, with every new commander in chief since Harry Truman holding a 66 percent approval rating and only a 10 percent disapproval rating, on average.
Unpopular presidents tend to hurt their party's chances in midterm elections. Former Presidents Ronald Reagan, Bill Clinton and Barack Obama all held negative or neutral approval ratings during the midterms, and their respective parties all lost seats during those elections.
Even though Trump has 21 months to improve his numbers, historically presidents have lost approval over their first term. Of the past presidents since Dwight Eisenhower, only George W. Bush entered the midterm elections with a higher net approval rating than he held in his first few weeks in office.
"However, there are plenty of reasons to question whether the pattern will hold true for Trump," writes FiveThirtyEight's Nathaniel Rakich. "For starters, all preceding presidents' approval ratings started from precipitous heights; many had nowhere to go but down.
"Trump, by contrast, is beginning his presidency relatively unpopular; he has plenty of room to improve. If newly elected presidents tend to revert to the mean, Trump is starting from a pretty average place."