(CNN) When it comes to the Russia investigation, it's not so much that the Trump team has a habit of "moving the goalposts," but that those goalposts have been rigged to roller skates and pushed downhill toward what feels like an inevitable end: where no matter what special counsel Robert Mueller finds, Trump will declare himself vindicated.

"No collusion," has been Trump's constant battle cry — he's tweeted it dozens of times since taking office -- even as he diminishes the status of aides ensnared in the probe (see: former foreign policy adviser George Papadopoulos ) to downplay their influence and the suggestion of, yes, collusion.

But to get a real sense of the degree and frequency with which the White House's story has changed, we need to rewind the tape back to just days after the 2016 election.

When Russian officials claimed their "experts" and "specialists on the US" had been in contact with people from both the Trump and Clinton camps, former Trump spokeswoman and erstwhile White House communications director Hope Hicks rejected the reports outright.

"It never happened," she told the Associated Press . "There was no communication between the campaign and any foreign entity during the campaign."

That was then. Over the subsequent 18 months, accounts of who from the Trump campaign met with whom, when, and for what reasons, have either conveniently evolved or reversed themselves entirely. Only the trajectory has remained the same, as Trump and his associates, with former New York City Mayor Rudy Giuliani the most recent example, continuously raising the bar — which is almost out of sight now -- for what they would accept as proof of wrongdoing.

The unqualified denials would soften over time. Even after it was revealed that his first national security adviser, Michael Flynn, had misled the White House about his post-election contacts with the Russian ambassador, Trump at a press conference told reporters, "I have nothing to do with Russia," adding: "To the best of my knowledge, no person that I deal with does."

A few days later, on February 20, 2017 , Sarah Sanders, then the deputy press secretary, echoed Trump.

"This is a non-story," she said, "because to the best of our knowledge, no contacts took place, so it's hard to make a comment on something that never happened." Shortly after, in March , Donald Trump Jr. told The New York Times that while he probably met during the campaign "with people that were Russian," nothing was never "set up" -- at least "none that I can think of at the moment. And certainly none that I was representing the campaign in any way, shape or form."

But those assertions were blown up a few months later, when the Times first reported on the campaign brain trust's meeting with a Russian lawyer, among others, at Trump Tower in June 2016. After releasing a public statement downplaying the gathering as brief and "introductory," focused on adoption policy, Trump Jr. changed his tune.

Here are two of his statements -- which we learned later on had been crafted with the guidance of his father and White House aides -- in response to the initial report, side-by-side:

A few days later, Trump Jr. decided to release the emails leading up to the meeting ahead of news outlets, effectively confirming reports he'd initially denied. Perhaps the most memorable exchange came right at the beginning, on June 3, 2016, when British publicist Rob Goldstone informed Trump Jr. that someone with ties to the Russian government had "some official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful to your father."

Trump Jr. replied that he was traveling but would be available the next week and, memorably , "if it's what you say I love it especially later in the summer." The meeting would take place on June 9, with Trump's son-in-law and adviser Jared Kushner and then-campaign chairman Paul Manafort also on hand. There's no evidence Trump was ever informed about what took place, but Trump Jr. did make three calls, in total, to blocked numbers before and after the meeting.

Who was on the other line? Talking to congressional investigators , Trump Jr. said he didn't remember.

The mixed, and ultimately misleading, initial public messages about the Trump Tower meeting marked the unofficial end of the blanket denial era.

They've also worked overtime to muddy the waters, litigating the meaning of "collusion" and often adding, as Trump did during an interview with the Times in late December , that "even if there was (collusion), it's not a crime."

"For something to be a crime, there has to be a statute that you claim is being violated," Trump's personal lawyer in the Russia investigation told CNN chief legal analyst Jeffrey Toobin, in a New Yorker story from earlier that month. "There is not a statute that refers to criminal collusion. There is no crime of collusion."

And that's true, up to a point. There is nothing in the criminal code that forbids or even legally defines "collusion." As former FBI director James Comey put it during a CNN town hall last month, "collusion is actually not a thing that exists under the federal laws of the United States. I had never heard the term until it appeared in the media." Still, the framing of the conversation has — with a push from the Trump team — now moved from, as Hicks put it, "There was no communication between the campaign and any foreign entity during the campaign," to the suggestion that, even if there was, it wasn't necessarily illegal.

Fast forward now a few months -- with a few more lawyers quitting in the meantime -- to the last couple weeks, as Giuliani emerged as the public face of Trump's defense. The big picture has become more complicated over time, with the emergence of Stormy Daniels and new revelations about Michael Cohen, the Trump lawyer who paid in October 2016 to keep Daniels quiet about an alleged, decade-old affair with Trump. ( The President has since reimbursed him .) But even with so much changing, the tactic has largely remained the same.

Over the past several days, Giuliani has argued that, even as Trump claims to be raring for a sitdown with Mueller and his team, the investigators do not have the power to compel his testimony. It's a legally dubious assertion given that past presidents have been subject to subpoenas, though none was compelled to sit down for an interview as part of a criminal investigation.

Whether Trump could be indicted is a stickier question. Giuliani told CNN last week that the Mueller team had "acknowledged" such a move wasn't on the table. "All they get to do is write a report," Giuliani said. "They can't indict. At least they acknowledged that to us after some battling, they acknowledged that to us." But there is no settled law here, just past DOJ opinions.

That's the status quo. The rest is just posturing. On the eve of the one-year anniversary of Mueller's appointment, Giuliani pretty well summed up the state of Trump's defense during an appearance on Fox News.

"When I ran (for office), they were looking for dirt on me every day. That's what you do. Maybe you shouldn't. But you do it," he said. "There is nothing illegal about that. Even if it comes from a Russian or a German or American, it doesn't matter."

That, crossed with Trump's long and ongoing Twitter campaign to discredit the probe as a "witch hunt," is the long and short of it. For all the drama and infighting, Trump and his team, even as it changes, has proven to be both agile and, well, creative.

No matter what comes down the pike, they have a rationalization or deflection ready to go -- even when it goes against the substance of what they once claimed.