President Donald Trump faces a House impeachment inquiry over his efforts to pressure the Ukrainian government to investigate his political rival, former Vice President Joe Biden, and publicly called on China to launch a similar probe this Thursday.

But most Republican senators have not rebuked the president for inviting foreign interference in next year's presidential election, underscoring their desire to evade Trump's fury.

They've either stayed silent on Trump's stunning conduct or accused Democrats of grossly overreaching with the proceedings.

At least 20 Republican senators would have to join all 45 Democrats and two independents to convict and oust Trump from office if an impeachment trial occurs.

Other than Romney and Sasse, no GOP Senators have forcefully condemned Trump's overtures to Ukraine or China, much less express any support for the impeachment proceedings in the Democrat-led House.

As Axios reported on Friday, Trump currently benefits from a big "red wall" of 36 GOP Senators from states where Trump's approval rating swings more favorably.

There's also no guarantee that all 45 Democratic senators would vote to convict Trump.

Visit Business Insider's homepage for more stories.

President Donald Trump faces a House impeachment inquiry over his efforts to pressure the Ukrainian government to investigate his political rival, former Vice President Joe Biden, and publicly called on China to launch a similar probe this Thursday.

But most Republican senators have not rebuked the president for inviting foreign interference in next year's presidential election, underscoring their desire to evade Trump's fury. They've either stayed silent on Trump's stunning conduct or accused Democrats of grossly overreaching with the proceedings.

The impeachment inquiry into Trump centers on an explosive whistleblower complaint filed in September which alleges that in a July 25 call with Ukrainian President Volodymyr Zelensky, Trump was "using the power of his office to solicit interference from a foreign country in the 2020 U.S. election."

The complaint detailed concerns that Trump used a July 25 phone call with Ukrainian President Volodymyr Zelensky to pressure the Ukrainian government to investigate the son of former Vice President Joe Biden, a Democratic presidential frontrunner, after withholding a nearly $400 million military-aid package.

Read more: Trump mentioned a wild conspiracy theory about the DNC and the Russia probe in his phone call with Ukraine's president

A memo summarizing the call released by the White House last Wednesday confirmed the substance of the complaint. It showed that after telling Zelensky that "we do a lot" for Ukraine in terms of military support, Trump asked him for "a favor" by investigating both Hunter Biden's business dealings and a debunked theory that Ukraine was somehow responsible for hacking the Democratic National Committee. (There is no evidence Hunter Biden engaged in corrupt activities in Ukraine.)

CNN later reported that in a call with Chinese leader Xi Jinping, Trump raised Biden's political fortunes as well as those of Sen. Elizabeth Warren, though its unclear whether he asked Xi to investigate either.

And in comments to reporters on Thursday, Trump said "China should start an investigation into the Bidens, because what happened in China is just about as bad as what happened with Ukraine," while standing on the White House lawn.

Asking a foreign government for material campaign aid is not only high unprecedented behavior from a president, but it could even violate campaign finance laws against soliciting aid from foreign nationals.

In a Friday tweet, Sen. Mitt Romney of Utah — who has criticized Trump in the past —wrote that "by all appearances, the President's brazen and unprecedented appeal to China and to Ukraine to investigate Joe Biden is wrong and appalling."

Also on Friday, Sen. Ben Sasse of Nebraska chided Trump, saying in a statement to the Omaha World-Herald, "Americans don't look to Chinese commies for the truth. If the Biden kid broke laws by selling his name to Beijing, that's a matter for American courts, not communist tyrants running torture camps."

Read more: Newly revealed text messages show Trump diplomats' internal turmoil over his pressure on Ukraine

In order for Trump to be removed from office, two-thirds or 66 members of the US Senate would have to vote to convict him of those articles of impeachment. Currently, there are 53 GOP Senators, 45 Democrats, and two independents who caucus with Democrats.

Republican senators have defended Trump and many face re-election in 2020

At least 20 Republican senators would have to join all 45 Democrats and two independents to convict and oust Trump from office if an impeachment trial occurs. Other than Romney and Sasse, no GOP Senators have forcefully condemned Trump's overtures to Ukraine or China, much less express support for the impeachment proceedings in the Democrat-led House.

Sen. Ron Johnson said "I know how President (Trump) talks. That's who he is,"in response to his pressuring Ukraine, and Sen. Marco Rubio of Florida described Trump pushing China to investigate Hunter as "not a real request." Both Senators represent states where Trump's approval rating is below water at net -11 and net -2, respectively.

Read more: Sen. Marco Rubio, an outspoken critic of China, says Trump's call for it investigate Joe Biden was not a 'real request'

As Axios reported on Friday, Trump currently benefits from a big "red wall" of 36 GOP Senators from states where Trump's approval rating swings more favorably. Fifteen of those senators are up for reelection in 2020, meaning that a vote to convict Trump could endanger their campaigns next year.

There are five Republican senators up for re-election in states where Trump's job approval ratings are underwater next year, but even if they all voted to convict Trump, it probably wouldn't be enough — giving those senators virtually no incentive to do so.

There's no guarantee that every Democratic senator would vote to convict Trump

There's also no guarantee that all 45 Democratic senators would vote to convict Trump. Red and purple-state Democrats are becoming fewer, and there are several who could seriously jeopardize their careers by a vote to convict Trump.

Sen. Joe Manchin of West Virginia, Sen. Doug Jones of Alabama are both among the more conservative Democrats in Congress, and are the only Senate Democrats representing states where Trump's approval rating is above water in Morning Consult at +20 and +22, respectively.

Jones is particularly vulnerable. He'll be up for re-election next year in deep-red Alabama in a cycle with presidential level-turnout, making him the only Senate Democrat whose 2020 re-election bid is rated a tossup by the Cook Political Report.

Read more: Trump is facing an impeachment inquiry, but history is on his side

Other relatively moderate Democrats who might not be sure bets to convict Trump include Sen. Krysten Sinema of Arizona, Sen. Jeanne Shaheen of New Hampshire, and Sen. Gary Peters of Michigan.

Trump may have violated centuries of presidential norms and federal law. But as The New York Times White House correspondent Maggie Haberman — who has covered Trump for years — pointed out in a Thursday Q&A, none of Trump's controversial behavior has held him back — so why stop now?

"He has led a consequence-free life despite enormously self-destructive behaviors over time," she said. "The divorces were marriages he wanted out of. The bankruptcies impacted his lenders most, not him. All of his behavior in 2016 ended with him winning the presidency. And the Mueller obstruction inquiry ended with no definitive answer."