"Obama was President up to, and beyond, the 2016 Election. So why didn’t he do something about Russian meddling?" Trump tweeted on Monday.
Mueller's indictments lay out evidence of a coordinated Russian information offensive that began in 2014.
In August 2016, the CIA told the White House that Russian President Vladimir Putin had personally ordered intelligence agencies to interfere in the 2016 election to help elect Donald Trump, The Washington Post reported.
Obama said nothing to the US public of the election interference until October 2016, weeks before the election. A later report from The Post quoted a senior Obama administration official as saying the response to Russia's hacking "is the hardest thing about my entire time in government to defend," adding, "I feel like we sort of choked."
In October 2016, Obama addressed Trump's frequent claims that the election was or would be rigged against him, essentially telling him to stop complaining.
"There is no serious person out there who would suggest somehow that you could even rig America’s elections — there’s no evidence that that has happened in the past or that it will happen this time, and so I'd invite Mr. Trump to stop whining and make his case to get votes," Obama said.
Trump tweeted that quote on Tuesday morning and responded to it by saying: "That’s because he thought Crooked Hillary was going to win and he didn’t want to 'rock the boat.' When I easily won the Electoral College, the whole game changed and the Russian excuse became the narrative of the Dems."
The Post's report also indicated that Obama may not have acted strongly because he, and every major polling firm, thought the Democratic nominee, Hillary Clinton, would win the election.
How do Trump and Obama's records on Russia compare?
Obama began his presidency in 2009 by having his secretary of state, Hillary Clinton at the time, press a "reset" button with Russian foreign minister Sergey Lavrov. Obama also never moved to provide Ukraine with weapons during the Russian-backed insurgency in the country.
In 2014, Russia invaded and illegally annexed Ukraine’s Crimea region to a muted US and NATO response. The next year, Russia entered the Syrian civil war with air support for Syrian President Bashar Assad, who immediately began bombing US allies.
Trump also authorized a strike on a Syrian air base that US intelligence sources believed was involved in chemical-weapons attacks on civilians. The Trump administration blamed Russia for the presence of chemical weapons in Syria, citing a 2013 agreement between Putin and Obama that said Moscow would step in and remove such weapons.
Additionally, Trump has taken on Russia's ally Iran with an explicit strategy to counter its influence in Syria, while Obama was seen as largely tolerant of Iran's agenda in Syria as he pursued the Iran nuclear deal.