Blogger Cameron Slater has told a court his posts are so popular it makes him a target for attack from people, such as former Conservative Party leader Colin Craig.
Whaleoil founder Slater, in a series of posts in 2015, alleged former Conservative Party leader Mr Craig sexually harassed his former press secretary Rachel MacGregor.
Ms MacGregor resigned suddenly two days before the 2014 election, having worked closely with Mr Craig from about the time he founded the Conservative Party three years earlier.
Mr Craig is suing Slater for defamation over his blog posts, while Slater is counter-suing Mr Craig over allegations the former politician made in a 12-page pamphlet he sent to 1.6 million homes trying to defend himself.
Slater says he was just doing his job as a journalist when he posted the allegations.
Under cross-examination by Mr Craig - who is representing himself - at the High Court at Auckland on Wednesday, Slater said people such as Nicky Hager in his book Dirty Politics had regularly attacked him because he was influential.
"That is why I'm targeted and continue to be targeted by people such as yourself," he told Mr Craig.
Mr Craig later asked Slater if his blogs were a political force that influenced votes and altered political outcomes, to which Slater replied "yes".
Slater said modern politics was a game that had only just graduated beyond the barbaric violence that often accompanied Ancient Rome's political life, saying "politics is a dirty game, played by dirty despicable people".
He said he did not hide his opinion in his posts and on some issues could be considered a political lobbyist.
However, he said he was never paid for blog posts but did receive income as a consultant providing media training or helping clients, such as politicians, prepare for hostile question and answer sessions.
Mr Craig titled his 12-page pamphlet sent to more than one million homes "Dirty Politics and Hidden Agendas".
The judge alone trial continues.