President Donald Trump on Monday questioned the legitimacy of last week's midterm elections, in which Democrats won control of both the House and Senate.

"Does anybody really believe that this 'Election' was honest," Trump wrote on Truth Social. "How could the Polls be so wrong??? Some early voting 'dumps' were so large that it was impossible to win, no matter how many people went to vote. It's all about the machines, which are far more important than the voter!" CNBC reported. He offered no evidence.

Why it matters: Days earlier, Trump told The New York Times he was "absolutely willing" to accept the results and that his administration would "probably work something out" with Democrats, The Guardian reported.

The backdrop

The post came six days after Republicans lost ground nationwide, including in GOP-held states such as Texas, Kansas, South Carolina and Iowa, according to CNBC.

After his 2020 loss, Trump claimed without evidence that widespread fraud cost him the race.

In California, Democrat Randy Villegas unseated Rep. David Valadao in the 22nd District. Related: why Central Valley voters say they flipped and Congress returns for the lame-duck session.