Three current and former governors featured at Tuesday night's Democratic National Convention opening pushed for over $13 billion in taxes, and enacted over $9 billion, a stark issue the GOP and anti-tax groups seized on in warning voters about the path the Democrats plan to take the nation.

According to Grover Norquist's Americans for Tax Reform, current Maryland Gov. Martin O'Malley has enacted $2.2 billion in taxes, Illinois Gov. Pat Quinn has pushed through $7 billion in taxes and former Virginia Gov. Tim Kaine, now a Senate candidate, sought $4 billion in new taxes.

"These governors are considered rising political stars and leaders in the Democrat Party. To most Americans, their tax hikes, both enacted and proposed, would have dire financial consequences," said ATR.

In fact, O'Malley is considered a top-tier 2016 presidential candidate who is expected to face Vice President Biden, Hillary Clinton and New York Gov. Mario Cuomo in the Democratic primaries.

ATR details their tax efforts here.