by Matthew Rusling

U.S. Democrats this week are making their case against President Donald Trump, while the defense is honing in on procedure, amid the third-ever impeachment trial of a U.S. president.

"The defense is focusing on procedure," Brookings Institution Senior Fellow Darrell West told Xinhua.

The Heritage Foundation Senior Legal Fellow Thomas Jipping told Xinhua the "defense believes that clear procedural limits will help them in the long run."

Indeed, Republicans have expressed outrage over the trial, constantly interrupting Democratic lawmakers and their counsel by harping on procedure and points of order, in the trial's drama-filled first week.

Democrats have countered by calling the trial "rigged," accusing Republicans of playing parliament in a bid to keep the public from seeing what Democrats said was evidence of Trump's wrongdoing.

MAIN ISSUE

Democrats' main accusation has to do with a phone call in July with Ukrainian President Volodymyr Zelensky.

During the conversation, Trump threatened to withhold aid to Ukraine in a bid to pressure Kiev to investigate the son of former Vice President Joe Biden, a potential rival of Trump in the 2020 elections. Biden's son has had business dealings in Ukraine.

Democrats said this is tantamount to betraying the nation's national security interests for the sake of Trump's own political gains, which they believe is an impeachable offense.

The White House continues to deny any wrongdoing, saying Democrats are simply seeking to derail the president in an underhanded way, in a bid to gain political power and deny Americans the right to choose their own president.

Republicans contend that the president never withheld aid, adding that treason, bribery or high crimes and misdemeanors are the only reasons a president can be impeached, according to the Constitution. They argue that the evidence against Trump qualifies for none of these.

MAIN ARGUMENTS

While Democrats said they have a mountain of evidence against the president, the party's main argument revolves around the phone call with Kiev.

The information Democrats have presented on the withholding of military assistance "for a political favor" is "compelling evidence of presidential abuse of power," West said, highlighting what he believes is Democrats' strongest argument.

Jipping highlighted both sides' arguments, noting that "Democrats say that the purpose they allege behind the president's actions -- soliciting foreign interference in American elections -- is an especially serious abuse of power and cannot be tolerated."

However, Trump's defense team contends the alleged offenses are "legitimate presidential actions," and that using impeachment as a political tool is a danger to the U.S. system of government, Jipping said.

Clay Ramsay, a researcher at the center for international and security studies at the University of Maryland, told Xinhua that Democrats' best argument is that Trump's threats to withhold aid to the Ukraine "broke the law ... and (that) Trump did so to engineer a foreign government's help in the next election."

For their part, the defense's best argument, according to Ramsay, is that "Ukraine received all the military aid appropriated by Congress, so there is no continuing issue here."

Despite the media fanfare, most experts believe the Republican-led Senate is unlikely to convict Trump.

"The Senate is poised not to remove Trump because nearly every Republican is toeing the party line. It is not clear that any Republican will vote to remove him from office," West said.

On Thursday, House Intelligence Committee Chairman Adam Schiff, who is heading the House's impeachment efforts, kicked off the day's proceedings by explaining he would reiterate information put forth at the previous day's proceedings.

"There will be some repetition of information from yesterday's chronology, and I want to explain the reason for it," Schiff told the Senate on Thursday, the trial's third day.

Despite having presented the same information the previous day, lawmakers will see information in videos, "therefore in a new context, in a new light of what else we know and why it compels a finding of guilt and conviction," Schiff said.