The 4th Congressional District is viewed as a strong Republican seat.
Eighteen candidates are running in the special election primary to replace Health and Human Services Secretary Tom Price in Georgia's 6th district on Tuesday.
Trump then recommended a book - "Reasons to Vote for Democrats" - that suggests there are none.
On Twitter, Trump said Monday that "The super Liberal Democrat in the Georgia Congressional race tomorrow wants to protect criminals, allow illegal immigration and raise taxes!"
If Ossoff captures 50 percent in the primary, which is crowded with 18 contenders, he will avoid a June runoff with a Republican candidate.
Ossoff pledges to fight Trump when he "embarrasses" the country. But Trump only narrowly won the district in November after Mitt Romney had carried by over 20 percentage points in 2012.
In that sense, Trump's tweet is on-message and may be cheered by even Trump-skeptical Republicans for using his large megaphone to inject that message into the bloodstream the day before the critical vote.
"That area has changed; it's changing", said Dante Chinni, director of the American Communities Project at George Washington University.
The district always leans heavily Republican. The Georgia Sixth, which is about seventy per cent white, is one of the wealthiest districts in the country. And it's full of wealthier, more educated voters who just aren't that receptive to Trumpism or actively recoil from it.
The last time Democrats had a winning midterm election, in 2006, the Democratic Party was energized because of President George W. Bush's handling of the Iraq War. "We got stuck with Trump". Ingram was one of the people who split their ticket in 2016; she voted against Trump but for Tom Price. She's won statewide office and benefits from high name recognition from failed bids for governor and the U.S. Senate. When I asked if she could see herself voting for the Democrat, she said, "Absolutely".
"If we can flip the 6th, every Republican who thinks he or she is in a safe seat will think again", said Sherean Malekzadeh, a 52-year-old Ossoff supporter from Brookhaven.
Ossoff too has mostly stopped talking about Trump, to whom he owes so much of his success. Even Debbie Dooley, the Atlanta Tea Party chairwoman, told The Atlantic she was surprised by the Democratic turnout for what she called a "very safe Republican seat".
If Trump can win, maybe anyone can win! "We have to channel the great vengeance and furious anger we have for this administration into votes at the ballot box". "Ossoff is going to look for the support of college-educated women and independents", Galloway said.
Republican supporters were in for a bit of a shock when the IL local elections came to a close.