With control of committees in both chambers of Congress, Democrats can summon officials, demand documents and hold public hearings to scrutinise Donald Trump and his aides. (AFP pic)WASHINGTON: Donald Trump vowed a political comeback Sunday as the major parties clashed over Democrat threats to prosecute top administration officials after the president's Republicans lost control of Congress in midterm elections.

The devastating results in last Tuesday's vote leave Trump politically hamstrung as he enters the remaining two-year 'lame duck' period of his White House tenure, while opening the door to multiple investigations by the Democrat-controlled Congress of the president, his family and senior members of his administration.