President Donald Trump’s firing of FBI Director James Comey for investigating Michael Flynn, the former National Security Adviser, has backfired. After the president dismissed Comey who wrote a memo that Trump asked him to let go regarding Flynn, talk of impeachment became louder. However, experts believe it has no chance of removing Trump from office.

On Wednesday, the talk moved from speculations to a call from Texas Representative Al Green, a Democrat, to impeach the Republican 45th president of the U.S. He said at the House of Representatives that he would not be moved as Green pushed for Trump’s impeachment.

Obstruction of a lawful investigation

Green’s basis in seeking impeachment for the president is Trump’s obstruction of a lawful probe of his ties to Russia during the presidential campaign. What triggered Flynn’s resignation was his admission that the National Security Adviser misled Vice President Mike Pence about the conversation on sanctions with Russian Ambassador Sergey Kislyak, Time reported.

Trump had insisted that Comey was fired over the manner the FBI director handled the investigation in the private email server of Hillary Clinton. But Green said that by firing Comey, linking it to the Russian investigation, and threatening the ex-director on Twitter, Trump intimidated and obstructed the probe.

Republican agrees with Green

Republican Representative for Michigan Justin Amash said the exchange between Comey and Trump that the former FBI director described in the memo, but denied by the president, is a ground for impeachment. Independent Maine Sen. Angus King agrees with Amash that obstruction of justice is a serious offense.

However, King said it with reluctance and sadness. He later also sought for Comey to authenticate the memo.

But Time noted that impeachment is a complicated process. Proof of it is that only two presidents in U.S. history have been impeached but none were removed from office. To impeach a president, a resolution for impeachment must have the approval of a simple majority in the House of Representatives.

But with the Republicans in control of the Lower House, the impeachment has slim chances of moving forward.

Even if the impeachment would get approval in the house, a two-thirds majority in the Senate must convict the president. It did not happen in the case of President Bill Clinton in 1998 when he was accused of lying under oath to a federal grand jury and in 1868. Likewise, it did not happen to President Andrew Johnson who breached the Tenure of Office Act when he fired the Secretary of War. But both presidents were not convicted by the Senate and finished their terms.