In Trump's lawsuit in Arizona:
A Trump campaign attorney conceded in court on Thursday morning that he tried to enter hundreds of dodgy form-filed affidavits into evidence, even though their own investigation found that a subset of the sworn statements that they received were filled with lies and “spam.”
“This is concerning,” [said] Judge Daniel Kiley, ...
... The Trump campaign said it excluded the submissions of those who swore to lies, but they included the ones they could not prove were lying into evidence.
Judge Kiley replied that this did not show the remaining affidavits are trustworthy.
“That just shows you cannot disprove what’s asserted,” Kiley noted.
Does a lawyer ordinarily need to take steps to determine that the contents of an affidavit are actually true before submitting it (rather than merely excluding ones determined to be false)? If not, what is the reasoning behind the judge requiring it here? Trump's lawyer may have collected the text of the affidavits via an online form, but he then printed them and had them signed under penalty of perjury by the affiants, which to my non-lawyer sensibilities makes them no different than any other affidavits.