He is best remembered for calling the special session of the Tennessee General Assembly that ratified the 19th Amendment, which gave women the right to vote, in August 1920.

Roberts' support for the amendment and his unpopular tax reform initiatives divided the state Democratic Party and doomed his reelection chances.

Roberts gained the support of party bosses E. H. Crump, Hilary Howse, and Nashville Banner publisher E. B. Stahlman,[4] and defeated Peay in the primary by 12,000 votes.

[5] In the general election, Roberts defeated Knoxville judge Hugh B. Lindsay, 98,628 (62%) votes to 59,518 (38%) (turnout is believed to have been influenced by that year's flu epidemic).

[4] On June 7, 1919, Roberts performed the marriage ceremony for celebrated World War I Medal of Honor recipient Sergeant Alvin York and Gracie Williams in the Pall Mall community, in Fentress County.

Along with attacks from labor groups and farmers, Roberts was accused by Putnam County Herald editor E. L. Wirt of hiring a "disreputable" secretary.

[4] On August 9, following his victory in the primaries, Roberts called a special session of the General Assembly to consider ratification of the 19th Amendment, which would give women the right to vote.

Angry anti-suffragists tried to file an injunction preventing Roberts from certifying the legislature's vote, but the Tennessee Supreme Court ruled against them.

In the general election campaign, the Republican nominee, Alfred A. Taylor, ruthlessly attacked Roberts' tax reforms.

Democrats attempted to stoke racial fears by criticizing Taylor for supporting the Lodge Bill (which would have provided protections for black voters) when he was in Congress.