They don’t see eye to eye. Photo: Chip Somodevilla/Getty Images; Bill Ingalls/NASA

It is no secret that the idea of impeaching President Donald Trump has slowly evolved from a rage-filled liberal fantasy to a real, if remote, contingency should some of the worst suspicions about the president on the Russian or financial fronts prove credible — or if Trump uses his powers to stop investigations that might or might not bear impeachable fruit.

But if you want a particularly good indicator that the specter of impeachment is in the room if not on the table among Democrats, here it is: Senator Al Franken is warning Democrats to beware of a big problem with removing the 45th president from office: it would produce a 46th president named Mike Pence.

Here’s what Franken said in an interview published yesterday:

One of his party’s highest-profile lawmakers, Franken has pressed law enforcement officials to step up their scrutiny of Trump’s finances and has said “everything points to” collusion between Trump’s team and the Russian government. But he warned that the outcome of impeachment would not be the answer to Democratic dreams.

“Pence ran the transition and some of the very worst nominees, I felt — [EPA chief Scott] Pruitt, [Education Secretary Betsy] DeVos, [HHS Secretary Tom] Price, [Budget director Mick] Mulvaney — were Pence selections, clearly, I think,” Franken told IBT. “He’s ideological, I consider him a zealot, and I think that in terms of a lot of domestic policy certainly would be worse than Trump.”

Franken went on to allow that Pence might be less dangerous than Trump in the foreign-policy arena. But still, the weighing of the pros and cons between the president and vice-president is a bit of a first, at least among Democrats with the stature of the junior senator from Minnesota.

In the brief history of presidential-impeachment deliberations, the identity of the putative replacement has been an occasional issue. Under the succession rules then in effect, Senate president pro tem Ben Wade would have become POTUS had Andrew Johnson been convicted in 1868. That would have suited the “radical” Republicans trying to push Johnson out of office since Wade was one of their own.

When Watergate began to consume Richard Nixon’s presidency, he initially spoke of Vice-President Spiro Agnew — whom most liberals loathed and many Republicans considered a lightweight — as his “insurance policy” against impeachment. But then Agnew was suddenly forced to resign in October of 1973 due to an unrelated corruption scandal, and Nixon lost his impeachment “insurance.” Under the relatively new 25th Amendment to the Constitution setting up the presidential succession we are familiar with today, Nixon appointed House Republican leader Gerald Ford to replace Agnew. On the one hand, Ford was a hard-core loyalist to Nixon in his hour of need. On the other, he was sufficiently liked and respected across party lines to make him a palatable successor.

Al Gore was considered too integral a part of the Clinton administration to stand out to people in either party as representing a good or bad alternative to Bill Clinton during the GOP’s doomed effort to remove the 42nd president from office (though by all accounts, Gore was infuriated by the Clintonian behavior that weighed upon his own efforts to become president in 2000).

I’d say Pence would fall somewhere between Ford and Agnew on the spectrum of palatability to members of the opposition party in case of Trump’s impeachment and removal or resignation. He’d be perfectly acceptable to most Republicans if Trump quit or really had to be removed. Unlike the Democrats who confronted Nixon, of course, today’s don’t control the levers of impeachment (though they could well control the lower House after the midterms). So Franken is very likely contributing to a debate that won’t ultimately matter. But he is offering some of the fierier anti-Trump Democrats some food for thought.