After President Donald Trump lambasted former President Barack Obama on Twitter Thursday with “Obamagate” theories, Obama had one message: Vote.

Obama’s tweet succeeded a series of tweets from Trump, in which he talked about “Obamagate” and demanded that the former president to testify on Capitol Hill.

Obama has become the recent target of GOP leaders after he criticized the Justice Department’s decision to drop charges against Trump’s former national security adviser Michael Flynn as a threat to the “rule of law.”

The term “Obamagate” began circulating after the Trump administration sent lawmakers on Wednesday a declassified list of Obama administration officials who requested Flynn’s identity be “unmasked.”