(AFP) -- The 56-year-old former president is scheduled to attend campaign rallies in New Jersey and Virginia on Thursday to support Democratic party candidates for governor.

Voters in both states will decide the gubernatorial contests on November 7, one year after Donald Trump defeated Democrat Hillary Clinton and stormed into the White House on a wave of anti-establishment fury.

The races are a potential indicator of voter sentiment ahead of the 2018 midterm elections, which will be a major test for Trump and his Republican party.

"There are only two big elections this year, for governor in NJ and VA," political science professor Larry Sabato told AFP.

"What's at stake is bragging rights headed into the 2018 midterm elections," Sabato said.

It is unclear what Obama's message will be. The former US leader has remained largely detached from the political debate since leaving office on January 20, in keeping with presidential tradition.

Trump has meanwhile used his first nine months in the White House to methodically demolish key Obama administration policies.

After three months of vacation Obama began writing his memoirs. He has said little in public and granted almost no interviews.

The few times Obama broke his silence was to comment on issues of national importance, such as immigration, health care and climate change.

But the 44th president may be tempted on Thursday to take aim at Trump, who has frequently and publicly excoriated his predecessor.

(Photo: bet)