Some Democrats, who will take the House majority in January, are willing to say President Donald Trump may have committed impeachable offences. But that does not mean they will try to impeach him — at least not yet.

For several reasons, Democrats have been extremely cautious about the "I" word. They know it could backfire politically, and many of them were in office during President Bill Clinton's impeachment 20 years ago. New York Representative Jerry Nadler, the top Democrat on the House Judiciary Committee and the panel's likely incoming chairman, has called impeachment a "trauma."

Mr Nadler told CNN on Sunday that if it is proved Mr Trump directed his former lawyer to commit campaign finance violations, as was suggested by special counsel Robert Mueller in a new court filing, he believes it would be an impeachable offence. But Mr Nadler added, "Whether they are important enough to justify an impeachment is a different question."

It is unclear whether the distinction between an impeachable offence and impeachment itself will satisfy those in the Democratic base who are eager to kick Mr Trump out of office. But Democrats are walking that fine line, for now.

These are the five reasons why Democrats are not ready for impeachment yet:

Other shoes to drop

In filings on Friday, Mr Mueller's prosecutors asserted Mr Trump's former lawyer, Michael Cohen, committed campaign finance violations "in coordination with and at the direction of" Mr Trump. It is the first time they have directly tied Mr Trump to a federal crime.

The violations stemmed from payments Mr Cohen made to buy the silence of porn actress Stormy Daniels and former Playboy model Karen McDougal. Both women alleged they had affairs with Mr Trump, which the White House denies. Mr Trump also denies knowing about the payment, but the filing contradicts that claim.

There is likely more to come from Mr Mueller. Charges are expected related to emails stolen during the 2016 presidential election that could implicate some in Mr Trump's circle. And Mr Mueller could complete a larger report at the conclusion of his investigation.

If Democrats move to impeach Mr Trump, it will likely be for more than just campaign finance violations.

It could backfire

Democrats are aware of the price Republicans paid for Mr Clinton's impeachment 20 years ago. Both Mr Nadler and House Democratic leader Nancy Pelosi were in Congress at the time, and Mr Nadler sat on the Judiciary panel. Republicans were seen as overreaching, and that helped boost Mr Clinton's poll numbers and win Democrats seats in the 1998 midterm election.

Ms Pelosi was also under pressure to impeach President George W Bush in 2006 when she first became speaker of the House. She has said if Democrats had spent their first two years in the majority trying to impeach Mr Bush, voters may never have elected Barack Obama as president in 2008.

Republicans are also aware impeachment could backfire.

"I think it'll help the president get re-elected," Senate Majority Leader Mitch McConnell said on the possibility Democrats would move for impeachment. "This business of presidential harassment may or may not be quite the winner they think it is."

Who could be running against Trump in 2020? Show all 23 1 /23 Who could be running against Trump in 2020? Who could be running against Trump in 2020? Joe Biden The former vice president - poised to be a frontrunner - has announced his run. He recently faced scrutiny for inappropriate touching of women, but was thought to deal with the criticism well AFP/Getty Who could be running against Trump in 2020? Bernie Sanders The 2016 runner-up has announced that he will be running again in 2020 Getty Who could be running against Trump in 2020? Hillary Clinton The 2016 Democratic presidential candidate and former Secretary of State says she is “still considering” whether she will run again. Getty Who could be running against Trump in 2020? Pete Buttigieg The Indiana mayor and war veteran will be running for president. If elected, he would be the first openly LGBT+ president in American history. Getty Who could be running against Trump in 2020? Kamala Harris The former California attorney general will be running for president in 2020. Introduced to the national stage during Jeff Sessions’ testimony, she has endorsed Medicare-for-all and proposed a major tax-credit for the middle class. AP Who could be running against Trump in 2020? Elizabeth Warren The Massachusetts Senator has formally launched her bid for president in 2020. A progressive Democrat, she is a major supporter of regulating Wall Street. AP Who could be running against Trump in 2020? Beto O’Rourke The former Texas congressman told Oprah Winfrey that he “has been thinking about running for presidency”, but stopped short of formally announcing his bid to run in 2020. AFP/Getty Who could be running against Trump in 2020? Wayne Messam Mayor of the city of Miramar in the Miami metropolitan area, Wayne Messam has announced his bid. He intends to run on a progressive platform against the "broken" federal government. He favours gun regulations and was a signatory to a letter from some 400 mayors condemning President Trump's withdrawal from the Paris Climate Accord. Vice News Who could be running against Trump in 2020? Kirsten Gillibrand The New York Senator formally announced her presidential bid in January, saying that “healthcare should be a right, not a privilege.” Getty Who could be running against Trump in 2020? Cory Booker The New Jersey Senator has announced that he will be running for the presidency in 2020. If he secures the nomination he said finding a female vice president would be a priority. Getty Who could be running against Trump in 2020? John Delaney The Maryland congressman was the first to launch his bid for presidency, making the announcement in 2017. AP Who could be running against Trump in 2020? Julian Castro The former San Antonio mayor announced his candidacy in January and said that his running has a “special meaning” for the Latino community in the US. Getty Who could be running against Trump in 2020? Tulsi Gabbard The Hawaii congresswoman announced her candidacy in January, but is likely to face tough questions on her past comments on LGBT+ rights and her stance on Syrian President Bashar al-Assad. Getty Who could be running against Trump in 2020? Andrew Yang The entrepreneur has announced his presidential candidacy, and has pledged that he would introduce a universal basic income of $1,000 a month to every American over the age of 18. AFP/Getty Who could be running against Trump in 2020? Marianne Williamson The author and spiritual advisor has announced her intention to run for president. She had previously run for congress as an independent in 2014 but was unsuccessful. Getty Who could be running against Trump in 2020? John Kerry The former secretary of state has said he is still thinking about whether to run. Getty Who could be running against Trump in 2020? Michael Bloomberg The entrepreneur and former New York mayor– with a net worth of around $50bn – has said he will decide by the end of February whether to seek the presidency. AFP Who could be running against Trump in 2020? Howard Schultz Former Starbucks CEO Howard Schultz has not yet ruled out running for president in 2020, despite criticism that his bid could help re-elect Mr Trump by dividing the Democrat vote. AP Who could be running against Trump in 2020? Eric Holder The former attorney general has said he will decide in “the next month or so” whether to run as a 2020 presidential candidate. AP Who could be running against Trump in 2020? Eric Swalwell The California congressman said he is “ready to do this” and will decide before April whether to run. MSNBC Who could be running against Trump in 2020? Terry McAuliffe The former Virginia governor, who worked to elect Democratic governors during 2018 midterms, said there was a “50 per cent” chance he would run. AP Who could be running against Trump in 2020? Sherrod Brown The Ohio senator is still undecided about whether to run for president in 2020. Who could be running against Trump in 2020? Mitch Landrieu The former New Orleans mayor said he doesn’t think he will run for president, but “never say never”. AP Photo/Jacquelyn Martin

Republican buy-in needed

Ms Pelosi has called impeachment a "divisive activity" that needs buy-in from both parties to work. "If the case is there, then that should be self-evident to Democrats and Republicans," she said.

Mr Nadler has said the same, that there would have to be at least some Republican support if they take the step of initiating impeachment proceedings.

If the Democrats hold to that, it would mean Mr Mueller would have to produce a lot more evidence of Mr Trump's involvement in crimes. No Republicans have so far come close to supporting impeachment, and many moderate Republicans critical of Mr Trump lost their re-election races in November.

Former FBI Director James Comey tells MSNBC Trump is not yet an unindicted co-conspirator to charges but 'is certainly close'

Checking Trump in other ways

Democrats have tried to keep the public focus on investigating the president and moving forward on policy, such as improving infrastructure and lowering health care costs.

Several Democrat-led committees are expected to initiate investigations of Mr Trump and the White House, including on whether Russians used laundered money for transactions with the Trump Organisation. They will also try to protect Mr Mueller's investigation through legislation.

Freshmen lawmakers who won competitive districts and handed Democrats the majority have made it clear they do not want to focus on issues like impeachment.

Democratic Representative-elect Jeff Van Drew of New Jersey said shortly after the election that his constituents "don't just want to see us argue and investigate and have hearings."

What happens next?

In the end, even if the Democratic House approved articles of impeachment, the Constitution requires a two-thirds vote of the Senate to convict. And that would be unlikely in a Republican-led Senate.

And some Senate Democrats might be reluctant to support impeachment, as well, since several of them represent swing states.

"My concern is that, if impeachment is moved forward on the evidence that we have now, at least a third of the country would think it was just political revenge and a coup against the president," said Senator Angus King, I-Maine, on NBC's Meet the Press on Sunday. "That wouldn't serve us well at all. The best way to solve a problem like this, to me, is elections."