Georgia voters are set to decide the balance of power in Congress in a pair of high-stakes Senate runoff elections.

Tuesday’s voting will help determine President-elect Joe Biden’s capacity to enact what may be the most progressive governing agenda in generations. Democrats must win both of the state’s elections to gain the Senate majority.

Republicans are unified against Biden’s plans for health care, environmental protection and civil rights. But some fear that outgoing President Donald Trump’s brazen attempts to undermine the integrity of the nation’s voting systems may scare away Georgia voters.

At a rally in northwest Georgia on the eve of Tuesday’s runoffs, Trump repeatedly declared that the November elections were plagued by fraud that Republican officials, including his former attorney general and Georgia’s elections chief, say didn’t occur.

The president called Georgia’s Republican secretary of state “crazy” and vowed to help defeat him in two years. At the same time, Trump encouraged his supporters to show up in force for Georgia’s Tuesday contests.