They didn’t. Investigators realized early on that there was" no there there." Instead liberals have concentrated their efforts on trying to overturn the election in other ways: preaching violence, shutting down websites they came are fake news, demonizing anyone who disagreed with them as racists, fools, traitors and fascists (N Y Daily News did this repeatedly and it has cost them much of their blue collar readership), calls for impeachment, harassing Trump admi istration figures, no condemnations of the Antifa groups equipped with masks, 2’ by 4’s with nails in them to stab police horses.
In October 2016 President Obama said our election process was safe. To question his ability or truthfulness means that you are a bigot, according to the left for the last decade (not to mention misogynistic since his attorney general was a woman). The 1980s are calling, they want their foreign policy back as he told Romney in 2012.
“There is no serious person out there who would suggest somehow that you could even rig America’s elections, there is no evidence that has happened in the past or will happen in the future”.