It may seem counterintuitive, but the impeachment inquiry into Donald Trump – which entered a new phase on Wednesday – has some major potential upsides for the U.S. president.

With the Democratic-led House of Representatives likely to vote in favor of impeachment in the coming weeks and the Republican-majority Senate unlikely to convict, both parties are looking to make gains from the political process ahead in the run-up to the 2020 election.

There are clear risks for Trump – his protective "Red Wall" could break and moderates or undecideds could jump to the Democrats – but key metrics suggest there are positive trends for his reelection bid too, so long as Republicans stick with him. 

How could a drawn out impeachment process benefit the man the inquiry is targeting?

2020 battlegrounds

The U.S. electoral college makes the national vote an irrelevance to the result of the presidential election – Hillary Clinton won the popular vote in 2016 by a distance – and ensures that a handful of swing states are the principal battlegrounds.

Win those states, win the election.

Democratic candidate Michael Bloomberg, who undertook extensive data modelling before jumping into the nominating contest, has identified Florida, North Carolina, Pennsylvania, Michigan, Wisconsin and Arizona as decisive to the 2020 race.

Polling suggests all six states are trending away from the Democrats and in each a majority of voters are opposed to impeaching Trump. Nationally, a clear plurality is in favor of putting the president on trial.

The numbers suggest impeachment is already a drag on Democrats in the states they need to win. And public opinion appears to have flatlined on the issue – support for impeaching Trump skipped up when revelations about the whistleblower's report were released, but has stood still through the recent hearings on Capitol Hill.

Kevin Sheekey, Bloomberg's campaign manager, told CNN that his candidate entered the race because his modelling indicated Elizabeth Warren was best-placed to win the Democratic nomination – and would lose in all six states to Trump.

A Washington Post average published on Tuesday, which also includes Nevada and New Hampshire, found that a majority of voters in those swing states (51 percent) oppose impeachment against a national average of 43 percent.

New York Times-Siena College polling published in early November found between 51 and 53 percent opposing impeachment in each of the six swing states.

An eight-point lead for the anti-impeachment argument in the key 2020 battleground states is a clear benefit for Trump and negative for his potential Democratic challengers.

Money and mobilization

The Trump campaign and associated groups are hammering home the president's message that the impeachment process is a "witch-hunt," a partisan waste of money and time, and counter-attacking against the Democrats. 

Axios, citing Advertising Analytics, reported that Republicans have spent 6.8 million U.S. dollars on impeachment TV ads since the beginning of October – Democrats have spent 4.7 million U.S. dollars in the same period.

The site noted Trump is even monetarizing the inquiry in terms of merchandise: His campaign store features a "Bull-Schiff" t-shirt, attacking House Intelligence Chair Adam Schiff, and a "Where's Hunter?" t-shirt targeting Hunter Biden, son of Democratic contender Joe Biden.

The Trump base is mobilized by impeachment. Any thoughts that his supporters in 2016 might sit out 2020, frustrated by a mixed record on key promises, have been put to bed. 

The ad spending could also have implications for House and Senate races in 2020.

Republicans see impeachment anger as a tool to paring back losses in the 2018 midterms and Trump-supporting groups are pouring money into attacking Democratic representatives in swing districts. The tactic also gives the targeted representatives a tough choice in the expected House impeachment vote. 

Public opinion shifts

A lack of movement in Trump's approval ratings is an indication of how stubborn his support is. 

Even as backing for impeachment jumped when revelations about his dealings with Ukraine were revealed, his approval ratings stuck stubbornly within the 40-43 percent range, according to an average by FiveThirtyEight, where they have sat for the past year. Low-40s is bad for a president heading into an election year, but it looks to be his floor.

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The Washington Post polling average indicates 86 percent of Democrats are in favor and 87 percent of Republicans against, effectively mirroring the sharp divide in Congress.

If Trump's message resonates enough to shift public opinion, or the process drags, there's a risk for Democrats of being boxed in. Few of the candidates – Senator Amy Klobuchar is an exception – have left much wriggle room if the public mood turns against the Democratic approach.

2020 opponents

Trump's claim in a recent Fox News interview that he wants a trial in the Senate may seem dubious, given the risk of removal from office and damage to his credibility.

However, the impeachment inquiry was sparked by a whistleblower claim that Trump tried to use the powers of the presidency to damage Joe Biden. A trial would be an opportunity to hamper the prospects of the former vice president. 

Trump has already said that at a trial he would expect Biden and his son Hunter, a central figure in Republican counter-attacks, to be among those called to testify.

A further potential benefit for Trump is that a Senate trial would feature several of his potential opponents: Senators Warren, Sanders, Klobuchar and Booker would take part, associating them more closely with impeachment in swing states and keeping them off the campaign trail.

The impeachment inquiry and potential trial carry serious negatives for Trump, and many of the gains – such as voter mobilization and donations – are mirrored on the Democratic side.

But for all the allegations, counter-claims and outrage, impeachment is not all bad for the president.