Reporters and political commentators often express frustrated surprise at the steadfast support of President Trump from most Republicans in the House and Senate. But they shouldn’t — it has happened before.

In fact, when these critics refer back to the Watergate era as a time of bipartisan commitment to the rule of law over politics, they get it exactly wrong. Defending the president at all costs, blaming investigators and demonizing journalists was all part of the Republican playbook during the political crisis leading up to the resignation of President Richard Nixon.

Despite the fact that 32 people and three companies have been indicted so far by the special counsel, Robert Mueller, only four of 11 Republican members of the Senate Judiciary Committee joined Senate Democrats earlier this year in an effort to protect Mr. Mueller’s investigation. The House majority leader, Kevin McCarthy of California, said in June that he thinks “the Mueller investigation has got to stop.” Senator Rand Paul of Kentucky and the House Intelligence Committee chairman, Devin Nunes of California, have joined Mr. Trump in calling the investigation a “witch hunt.”

Dispiriting, perhaps, but not shocking or unprecedented. In late 1972, when a Democratic congressman, Wright Patman of Texas, began to investigate connections between Mr. Nixon’s aides and the Watergate burglary, the House Republican leader, Gerald Ford of Michigan (who later succeeded Mr. Nixon as president), called it a “political witch hunt,” according to the historian Stanley I. Kutler in his book “The Wars of Watergate.”