Republicans in the Senate have voiced skepticism over recent polls that show Democratic nominee Joe Biden expanding his lead over President Donald Trump.

In nationwide polls, President Trump trailed Biden by almost 10 points. The president is also falling behind in critical swing states including Pennsylvania, Arizona, Michigan, and Wisconsin.

“I think they’re in all likelihood underreporting support for the president. That’s what we saw in 2016,” Sen. John Cornyn (R-Texas) told The Hill. “I’m always a little skeptical when I see a poll.”

“Because of previous years’ poll being wrong, I think it’s legitimate to question. I don’t know whether they’re accurate or not,” Senate Finance Committee Chairman Chuck Grassley (R-Iowa) echoed Cornyn’s comments about a recent poll showing Biden and President Trump in a dead heat in Iowa.

Biden on Tuesday shrugged off his lead, saying, “I know the polling data is very good, but I think it’s really early. It’s much too early to make any judgment. I think we’ve got a whole lot more work to do.”

The former vice president stepped up his attacks on President Trump over his response to the CCP Virus (coronavirus) pandemic and nationwide unrest in the wake of George Floyd’s death, accusing the president of having “waved the white flag and left the field of battle” against the resurgent pandemic. 

Biden also confirmed that he will not be holding campaign rallies due to the virus while saying that he “can hardly wait” to test his cognitive abilities against those of the president in the fall debates. 

“I’ve been tested and I’m constantly tested,” Biden said when asked if he has been tested for cognitive decline over growing public concerns about his health. “Look, all you gotta do is watch me, and I can hardly wait to compare my cognitive capability to the cognitive capability of the man I’m running against.”

President Trump has dismissed those polls that show him losing to Biden, saying that many of them were “fake” and a form of “suppression.”

“It’s like with Hillary [Clinton],” the president said. “I was behind in the polls in the battleground states in every poll, and then I ended up winning all those states … and winning states that I wasn’t even supposed to be in play.”

“We won Michigan, we won Wisconsin—great states—so we were behind and I don’t believe we’re behind because, in my polls, we’re ahead. We have polls, and in my polls, we’re ahead,” he added.