To convict on impeachment, they need 67 votes. But for this, they would only need 60 to break a filibuster. This would need only 60 votes to overcome a filibuster.
According to Fox News:
Senate Majority Leader Chuck Schumer Thursday did not rule out bringing legislation to bar former President Donald Trump from office if he is not convicted at the ongoing Senate impeachment trial.
Democratic senators have discussed in recent weeks that if they cannot secure the 67 votes needed to convict Trump that they might invoke the 14th Amendment of the Constitution to do the same.
Schumer, D-N.Y., was asked about the possibility in a press conference ahead of the impeachment trial proceedings Thursday.
“We’re first going to finish the impeachment trial and then Democrats will get together and discuss where we go next,” Schumer replied.
The 14th Amendment to the Constitution says that Congress can bar people who “engaged in insurrection or rebellion” against the U.S. from holding office. It was originally meant to prevent former Confederates from serving in the government after the Civil War.