A grand jury would be able to issue subpoenas as part of a criminal investigation into renewed allegations that Democratic officials tried to smear Donald Trump during his 2016 campaign by falsely alleging his campaign was colluding with the Russian government.
Going to be really difficult to bring it to trial when Paul Manafort was literally convicted of conspiring with Russia. Like they may be able to pander off a Grand Jury on probable cause, but they're going to have to address at some point that Obama looking into Trump's Russian ties was justified since Manafort literally was working with Russia and Manafort was leading Trump's 2016 campaign. Things adjacent tend to cause inquiry.