In short:
Donald Trump retaliated after Barack Obama delivered scathing criticisms of the incumbent during Democratic rallies in Ohio and Michigan.
Mr Trump labelled Mr Obama "grossly incompetent" and falsley claimed Democrat candidate, Abdul El-Sayed is a "Jihadist"
What's next?
Nationally, polls suggest the Democrats could regain control of the House of Representatives, but face more competition in the Senate.
US President Donald Trump has retaliated after his Democratic predecessor, Barack Obama delivered scathing criticisms of the incumbent during rallies in Ohio and Michigan.
Mr Trump labelled the former leader "incompetent" during his own rally in Michigan, which came one day after Mr Obama campaigned alongside Democratic Party candidate Abdul El-Sayed in the same state.
"Obama was a grossly incompetent President! He paid off Iran with $Billions, and gave them a road to a Nuclear Weapon." Mr Trump wrote in a post on social media.
The US president also slammed Mr Obama for supporting US Senate candidate Abdul El-Sayed.
The hit at Mr El-Sayed comes after Mr Trump and Republican candidate Mike Rogers have repeatedly tried to tie Mr El-Sayed to the Muslim Brotherhood, falsely branding the Democrat a "jihadist."
In the same post on social media, Mr Trump called Mr El-Sayed a "Fake Doctor, who runs what is considered to be the WORST CLINIC IN AMERICA."
"Michigan doesn't want an arrogant, Open Borders, Fake Doctor, Jihadist, whose reputation will only get worse as more information is revealed."
Mr Trump has been telling voters to view the midterm elections as if he were on the ballot, and on Saturday Mr Obama did just that.
Obama unleashes
Ten days out from the November 3 elections that will determine control of the closely divided Congress, Barack Obama took to the campaign trail to accuse the Republican president of corruption.
Mr Obama spared no mercy when it came to criticism surrounding Mr Trump's strategy for Iran, and skewered the gilded aesthetic he has applied to White House renovations.
Taking aim at new renovation projects across the US capital, including the National Mall's Reflecting Pool and the construction of a White House Ballroom.
The decorations added to the Oval Office during Mr Trumps second tenure were also not safe from critique.
"He's got the White House looking like Saddam Hussein opened a Cheesecake Factory,"Mr Obama said.
The former president has retained considerable popularity among the Democratic base, which he is keen to leverage to support his party's candidates.
In both states, Mr Obama blamed the Trump administration for the rising cost of living, one of the top voter concerns.
"The current president chose to make a series of bad decisions," Mr Obama said in Cleveland, Ohio, where he rallied in support of former Democratic senator Sherrod Brown.
"Most importantly, he decided to start an unnecessary war that nobody asked for."
The war on Iran has sent oil prices soaring as Tehran effectively blocked the Strait of Hormuz after being attacked.
"After two years of chaos and cruelty and corruption and incompetence, the likes of which we have not seen in the modern era, you get a chance to say, enough is enough," Mr Obama said.
Later, in Michigan he campaigned for Abdul El-Sayed, from the party's left wing, who is in a close race with Republican Mike Rogers for the US Senate.
"Imagine the power duo of Abdul and Elissa," Mr Obama said, referring to the incumbent Democratic Senator Elissa Slotkin, who is not up for election this year.
"You got a Muslim man, you got a Jewish woman fighting for you in the United States Senate. That's something, Michigan, you can be proud of."
Obama says 'don't procrastinate'
The former president also urged voters to cast their ballots as soon as possible since early voting is already open in both states.
"Don't procrastinate, don't equivocate," Mr Obama said.
Polls in Ohio give Democrats a slight lead in both races, but results are expected to be close.
Nationally, polls also suggest that Democrats could regain control of the House of Representatives but face a much more competitive contest for the Senate.
AP/AFP
