Asked about that familiar charge, Orman shrugged it off before his own rally, saying he has become the worst nightmare for both parties, someone ready to challenge the status quo in Washington.
With no Democrat on the ballot, Orman has tried to become a fusion candidate, bringing along disaffected Republicans, independent voters and Democrats in the Sunflower State.
"If there's one thing my campaign stands for, it's declaring our independence from politics as usual," Orman tells his backers.
Orman brought his "Breaking the Gridlock" tour to both Wichita and the Kansas City suburbs on Sunday; Roberts again trotted out Kansas icon Sen. Bob Dole and others in a series of stops in Johnson County, to the south and west of Kansas City - a county that turned out big numbers for both John McCain in 2008 and Mitt Romney in 2012.
Early vote edge to the GOP in Kansas
A look at the early vote in Kansas shows that Republicans have a strong edge, almost 24 percentage points over Democrats, with independents returning just 15% of the ballots so far.
That's led to questions about whether Orman - without any party structure to help him get out the vote - can win the ground game here on Tuesday.
"It's not easy," Orman's campaign manager to the Associated Press last week.
If you were looking for clues as to who has the momentum from their Sunday rallies, nothing really stood out.
Roberts drew about 100 backers at a rally for more conservative Republicans; Orman had about the same number of people show up in a local park.
Of the last ten major polls on the Kansas Senate race, Orman has led five, Roberts has led the other five - most within the margin of error.
While it may not get the attention of Iowa, North Carolina or Kentucky, this is a crucial race here in the Sunflower State, as an upset win by Orman could derail the hopes of Republicans to take control of the U.S. Senate.
Roberts admitted to reporters that Orman has been able to tap into the frustration of voters about the Congress.
"What we've been trying to point out on the Republican side is that we share their frustration, we share their anger," Roberts told reporters.
"There's no question, we are the number one threat to the status quo," said Orman.
And now, after months of battling, the voters here in Kansas will have the final say on Tuesday.