Observers say Cassidy is playing it safe: Leading in the polls with favorable national tailwinds and an army of outside groups flooding the airwaves on his behalf, the congressman has given himself few opportunities to surrender his advantage with a major gaffe, or even an unflattering moment.
"This is the political equivalent of the four corners offense or the slowdown," said Pearson Cross, a University of Louisiana at Lafayette political scientist. "I think he feels like he has a good advantage and this a just a way to kind of freeze the game."
In contrast to Cassidy's strategy of laying low, Landrieu has been barnstorming Louisiana -- holding three or four events per day from one end of the state to the other. On Tuesday, she was in Gretna, just across the Mississippi River from New Orleans. By Thursday, she was in Shreveport in the far Northwest corner of the state.
Cassidy was supposed to appear in Shreveport with Rick Santorum Wednesday night at a Baptist church. But he canceled his appearance at the last minute. His campaign said the schedule change was due to votes in Washington.
Another national surrogate, Republican National Committee Chairman Reince Priebus, campaigned for -- and without -- Cassidy on Thursday.
Landrieu has accused Cassidy of trying to run out the clock against the backdrop of scrutiny over his record as a part-time physician and teacher at Louisiana State University. A local blog recently published some of his time sheets, prompting LSU to look into the matter.
Cassidy has said he did nothing wrong. But Landrieu has repeatedly said he may have committed payroll fraud.
Even as Cassidy the candidate has been a non-factor on the campaign trail this week, allied groups have flooded TV and radio with ads making the case on his behalf. Conservative groups are on pace to dish out more than $5 million on runoff ads for Cassidy. Pro-Landrieu groups are on pace to spend only about $216,000.
While Cassidy's non-presence and the LSU scrutiny haven't helped him, Republicans remain confident about his chances of winning on Saturday and notching a ninth GOP pickup. He's run a consistent campaign rooted mostly in tying Landrieu to President Obama, who is deeply unpopular in the state.
The same playbook propelled Republicans to victory all across the country this year.
"It has been remarkable the extent to which his campaign has been a generic Republican campaign," said Cross.