MACON, Ga. (AP) — Democrat Michelle Nunn is ramping up her attacks on Republican David Perdue as the race for Georgia's open Senate seat heats up.

The two met for their first candidate forum Thursday and Nunn quickly set the tone by touting her ability to work across party lines while portraying Perdue as an obstructionist who would continue Washington gridlock.

Perdue didn't respond to the attacks, focusing instead on criticizing the policies of national Democrats and arguing Nunn would be a proxy for President Barack Obama.

The Georgia race is one of the most closely watched this year as Republicans make a push to take control of the Senate for the last two years of Obama's term.

Libertarian Amanda Swafford, who will also appear on the ballot, was not invited to the forum.