Left-wing filmmaker Michael Moore was more than disappointed with Hillary Clinton’s selection of Sen. Tim Kaine (D-VA) as her running mate, predicting Kaine would not excite the liberal base to go to the polls.

Show me 1 voter gained by naming Tim Kaine. Att'n Hillary campaign: It's not Trump who'll beat u. It's the people who are going to stay home — Michael Moore (@MMFlint) July 23, 2016

He contrasted Clinton’s pick with Indiana Governor Pence, Donald Trump’s running mate, who Moore predicted would excite the GOP base.

Tim Kaine. Sigh. Trying to win votes from a middle that's no longer there. Shows old political thinking. Trump picked VP to excite the base — Michael Moore (@MMFlint) July 23, 2016

Trump also took to Twitter to point out that the centrist Kaine, whose selection reportedly allowed Wall Street executives to breathe sighs of relief, represents the “opposite of what Bernie stands for.”

“Bernie fought for nothing,” Trump Tweeted.

The Bernie Sanders supporters are furious with the choice of Tim Kaine, who represents the opposite of what Bernie stands for. Philly fight? — Donald J. Trump (@realDonaldTrump) July 23, 2016

Tim Kaine is, and always has been, owned by the banks. Bernie supporters are outraged, was their last choice. Bernie fought for nothing! — Donald J. Trump (@realDonaldTrump) July 23, 2016

Many progressive activists and Sanders’s supporters like Moore believed that Clinton’s selection of the centrist Kaine was a sign that she was taking their votes for granted. Perhaps aware of Kaine’s liabilities, Clinton introduced Kaine at Saturday’s rally in Miami as a “progressive who gets things done.”