WEST PALM BEACH, Fla. — President Donald Trump is again attacking his predecessor on Twitter, asking why he didn’t do more to prevent Russian election meddling.

Trump’s tweet on Monday says: “Obama was President up to, and beyond, the 2016 Election. So why didn’t he do something about Russian meddling?”

Trump raised similar questions over the weekend, after an indictment from special counsel Robert Mueller charged 13 Russians with a plot to interfere in the U.S. presidential election.

President Barack Obama in late 2016 defended his administration’s response to the Russian meddling, also saying he had confronted Russian President Vladimir Putin that September, telling him to “cut it out.”

Trump repeatedly challenged the veracity of the mounting evidence about Russian interference in the 2016 campaign. Over the weekend he denied ever casting doubts.