Updated

By all appearances, it was another tough week for President Trump as he runs for re-election.

As the coronavirus continues to wreak havoc, the president had reversed course and canceled next month’s GOP convention events slated for Jacksonville, Florida. And a new batch of public opinion polls – both nationally and in key battleground states – indicated large leads for Democratic challenger Joe Biden.

FOX NEWS POLLS: BIDEN TOPS TRUMP IN MICHIGAN, PENNSYLVANIA, AND MINNESOTA BATTLEGROUNDS

But with three and a half months to go until November’s general election, the president’s new campaign manager remains very optimistic.

“This is will be a knock-down, drag-out fight to the very end,” Bill Stepien predicted on Friday as he held his first briefing with political reporters.

Stepien advised to “take national polls with a grain of salt” and added that around the Trump campaign headquarters “we don’t pay a lot of attention to them.”

It was the same message – though less blunt – that’s been repeatedly delivered for a couple of months running by Trump. Making the case that the surveys under sample Republican voters, Stepien argued that “national polls keep getting it wrong” and “miscalculate the electorate.”

Stepien harkened back to the 2016 election – where an average of the final public opinion polls in the key battleground states of Michigan, Pennsylvania and Wisconsin all showed Democratic nominee Hillary Clinton with the edge heading into Election Day. Trump narrowly carried all three states -- the first Republican to win those states in a quarter century – as he won the White House.

Pointing to political pundits, Stepien emphasized that “the same people who were predicting a landslide for the president in January are the same ones who are predicting a landslide for Joe Biden now. They are the same experts who gave Donald J. Trump no chance in 2016.”

And highlighting the Trump campaign’s own polls, he said “we know here at our headquarters what our internal numbers say and it’s why we have a quiet confidence in our plan and in our mission.”

Stepien said that the plan has “multiple pathways to 270 for the president.”

He touted that with just over 100 days to go until Election Day, “we have many advantages over Joe Biden. We have a better team. We have a better ground game. We have better fundraising, digital, data, and most importantly a better candidate with a better record.”

And Stepien highlighted that Trump’s digital and advertising campaigns are “simply second to none. It provides the president such an advantage down the stretch to be able to contact, reach, and touch voters from afar when traveling is little harder these days.”

Presidential elections where an incumbent is running for a second term in the White House are often about that president – and that’s the case right now in the 2020 showdown between Trump and Biden. The top issues are currently the coronavirus and an economy flattened by the pandemic – and the president’s performance and record on both issues.

But the president and the Trump campaign are trying to turn the spotlight back onto the former vice president and presumptive Democratic nominee.

“Joe Biden is largely undefined for most Americans. A lot of Americans know of Joe Biden. Far fewer know much about Joe Biden. Our job here every day is to change that and define him for who he is today,” Stepien emphasized.

The president has repeatedly spotlighted his law and order approach to the national protests in urban areas across the country over police brutality and system racism – and Trump’s campaign has tried to tag Biden as a “puppet” of what they call the "radical left."

In ads running in key battleground states, Trump’s team is trying to tag the former vice president as a supporter of the movement to defund the police. Biden has said on multiple occasions that he doesn’t support such a move. The campaign’s push appears to be a move to try and restore Trump’s fortunes with the suburban voters he captured in 2016 who later fled the GOP in 2018.

TEXAS TOSS UP: POLLS SHOW BIDEN AND TRUMP TIED

Recent public opinion polls indicate that the once ruby red state of Texas is all tied up between Biden and Trump. And the Biden campaign this month went up with their first TV spots in the state with the second largest haul of electoral votes, behind California.

Stressing that Texas will remain red, Stepien said ”I would invite the Biden campaign to play in Texas. They should play hard. They should go after Texas really, really, heavily, spend a lot of money in the Houston and Dallas media markets.”

And discussing Texas as well as Arizona and Georgia – two other longtime Republican states in presidential elections that the latest polling suggests are now toss ups, he said “these are all states that come back home. We had the same conversations 4 years ago and we saw they all turned out on election night in November.”

Stepien also pointed to opportunities to expand upon the 2016 map in states narrowly won by Clinton, such as Minnesota, New Hampshire, Maine and Nevada.

Asked about Minnesota – where a Fox News poll released on Thursday indicated Biden with a double digit lead – Stepien told Fox News’ Peter Doocy “there are enough votes in Minnesota to win. Now we have the resources to get them.”

And he added that “we are bullish that Minnesota is a state that can come around.”

Fox News' Peter Doocy and Patrick Ward contributed to this report.