Between 2017 and now, almost the entire House Democratic caucus and one Independent congressman — have come out in favor of beginning an impeachment inquiry against President Donald Trump.

Dozens of members came out in favor of impeachment after the release of special counsel Robert Mueller's report, and their ranks grew after an explosive whistleblower complaint involving Trump came out in September.

In the complaint, a whistleblower alleges that Trump is "using the power of his office to solicit interference from a foreign country in the 2020 U.S. election" by pushing Ukraine's president to investigate the son of a political rival.

On September 24, House Speaker Nancy Pelosi announced that she would be backing an official impeachment inquiry into Trump.

Here's a look at who supports the ongoing impeachment inquiry.

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Officially over half of the members of the House of Representatives now support an impeachment inquiry into President Donald Trump after an explosive complaint from an intelligence community whistleblower was released this month.

In the complaint, the whistleblower writes that based on his conversations with "half a dozen US officials," he concluded that the "president of the United States is using the power of his office to solicit interference from a foreign country in the 2020 U.S. election," specifically from Ukrainian President Volodymyr Zelensky.

Trump, his personal attorney, and the White House's own memo of the call revealed that Trump, after emphasizing how much military aid the US gives to Ukraine, asked Ukraine's president for "a favor" by investigating CrowdStrike, a cybersecurity firm retained by the DNC, and an oil and gas company which had Hunter Biden, the son of former Vice President Joe Biden, on its board.

"For the past several months, we have been investigating in the committees and litigating in the courts whether Congress can exercise its full Article I power, including the constitutional power of approval of articles of impeachment," Pelosi said at the press conference.

She slammed Trump's actions as having "revealed the dishonorable fact of the president's betrayal of his oath of office, betrayal of our national security, and betrayal of the integrity of our elections" in getting behind a formal impeachment inquiry.

Read more: A formal impeachment inquiry has been launched: Here's everything we know about the whistleblower complaint and Trump's phone call with Ukraine's president

For the first half of the Trump presidency, Democratic leaders urged prudence and restraint while the country awaited the outcome of former special counsel Robert Mueller's investigation into Russian interference in the 2016 election.

While Mueller's prosecutorial team concluded that Russia interfered in the 2016 election, they did not charge anyone associated with the Trump campaign with collaborating with Russia to influence the outcome of the election.

The report did not come to a "traditional prosecutorial decision" about whether Trump had obstructed justice, but laid out 11 possible incidents where Trump could have obstructed justice, including Trump firing James Comey and his attempts to fire Mueller himself.

At the time, Mueller made it explicitly clear that the report did not exonerate Trump, and that his office had no ability to charge Trump with a crime because of existing Department of Justice policy prohibiting prosecutors from indicting a sitting president — leaving the next steps up to Congress.

Even since the Mueller report came out, Speaker Pelosi backed more congressional investigations into Trump while still claiming that impeachment would be incredibly divisive, and should only be a last resort.

But the bombshell nature of the whistleblower complaint significantly turned the tide in favor of impeachment. The White House memo of the call and Trump's own comments about the situation have already confirmed the key details of the complaint, that Trump wielded the power of his office for political gain.

Read more: The notes on Trump's call with Ukraine's president hint at a quid pro quo over investigating Joe Biden's son

"There's a lot of talk about [Biden's] son, that Biden stopped the prosecution and a lot of people want to find out about that so whatever you can do with the Attorney General would be great," he told Zelensky.

These are all the house members who currently support the impeachment inquiry:

Now, well over half of the House of the Representatives support the ongoing impeachment inquiry, with just a handful of House Democrats holding out.

But it doesn't mean that all those members will be guaranteed to vote for articles of impeachment if and when articles of impeachment come to the House floor. If a simple majority of members of the House voted to pass articles of impeachment, the US Senate would then hold a trial to convict or acquit Trump based on those charges.

There are multiple house committees conducting the impeachment inquiry, and House leadership is still determining whether to keep the scope of the inquiry solely focused on Trump's alleged conduct with Ukraine, or include articles related to the instances of possible obstruction of justice outlined in the Mueller report.

Read more: An overwhelming majority of Democrats think the House should impeach Trump. So do 15% of Republicans.

Many members from highly competitive districts that Trump won in 2016 only spoke out in favor of an impeachment inquiry after the substance of the whistleblower complaint came to light.

Meanwhile, the House pursuing an impeachment inquiry is gaining popularity among the American public.

New polling from Morning Consult released Thursday found that support for impeachment among all Americans increased by nine percentage points and doubled among Republicans (with a margin of error of 2%) over the course of just four days as more information about the Ukraine scandal became public.

Read more:

POLL: Americans support the impeachment inquiry into Trump, but they worry about electoral blowback

The whistleblower who filed an explosive complaint against Trump is reportedly a CIA officer once assigned to the White House

Here are all the documents that lay out the allegations in the Trump-Ukraine scandal