President TrumpDonald John TrumpA better VA, with mental health services, is essential for America's veterans Pelosi, Nadler tangle on impeachment, contempt vote Trump arrives in Japan to kick off 4-day state visit MORE on Thursday night dismissed former President Obama's reemergence on the campaign trail ahead of the November midterm elections, arguing it could fire up his own base.

“By the way, he’s campaigning again. That’s good news. When I was running, I swear, I thought he campaigned harder than Hillary ClintonHillary Diane Rodham ClintonHillary Clinton slams Trump for spreading 'sexist trash' about Pelosi Gillibrand seizes on abortion debate to jump-start campaign DNC boss says candidates to be involved in debate lottery MORE. And we won big,” Trump said at a rally in Las Vegas on Thursday evening.

ADVERTISEMENT

Obama burst back onto the scene earlier this month in a speech in Illinois that included blistering rebukes of Trump’s performance while in office on everything from his tax plan to his response to the deadly white nationalist rally in Charlottesville, Va., last year.

The former president also travelled to California to rally for several House candidates, including some running in Republican-held districts, and Ohio to campaign with Democratic gubernatorial candidate Richard CordrayRichard Adams CordrayHouse rebukes Mulvaney's efforts to rein in consumer bureau The road to the White House still goes through Ohio Rep. Tim Ryan announces presidential run MORE.

Obama will also travel to Philadelphia on Friday to rally with Democratic Sen. Bob CaseyRobert (Bob) Patrick Casey2020 Democrats put spotlight on disabilities issues Why Congress needs to bring back tax deduction for worker expenses Biden cements spot as 2020 front-runner MORE and Gov. Tim Wolf (D).

Obama had previously avoided the campaign trail since leaving office, wary of nationalizing tight state races or rallying GOP voters in some areas.

Trump's comments came during a rally in Nevada on behalf of Sen. Dean HellerDean Arthur HellerThis week: Barr back in hot seat over Mueller report Trump suggests Heller lost reelection bid because he was 'hostile' during 2016 presidential campaign Trump picks ex-oil lobbyist David Bernhardt for Interior secretary MORE (R-Nev.), one of the most vulnerable Republicans running for reelection in November.