House Dems apparently are already thinking along those lines, including an extended review of issues related to Russia, based on recent court filings. From a report at The Washington Post:
The House said in court filings Monday that more impeachment charges against President Trump are possible based on the testimony they are seeking from his former White House counsel and grand jury material they want to review from the Russia investigation.
“The Committee is continuing to conduct its inquiry into whether the President committed other impeachable offenses,” attorneys for the House Judiciary Committee wrote. “The Committee’s investigations did not cease with the House’s recent impeachment vote."
That assertion was made in response to an argument from attorneys for the Department of Justice that the impeachment vote has undercut the rationale behind the House’s demands.
“It is far from clear that the Committee . . . will have any further role in the impeachment process at all,” they wrote. “The Committee has referred articles of impeachment to the House; the House has approved those articles; once the articles are transmitted to the Senate, the next steps are for the Senate to determine.”
Where is this heading? The Post provides insight:
The dueling memos came in two separation-of-powers lawsuits pending at the federal appeals court in Washington. The U.S. Court of Appeals for the D.C. Circuit next week will review the two cases in back-to-back hearings.
In the first case, House Democrats are asking the court to enforce a subpoena for Donald McGahn, who lawmakers have said is the “most important” witness in whether Trump obstructed justice in special counsel Robert S. Mueller III’s investigation of Russian interference in the 2016 presidential election.
The second case involves the House’s effort to gain access to certain secret grand jury material from Mueller’s probe.
Both lawsuits were filed before the formal start of the impeachment proceedings and last week’s House vote, which centered on Trump’s alleged effort to pressure his Ukrainian counterpart to investigate a potential 2020 political rival.
Ahead of oral argument, set for Jan. 3, the D.C. Circuit judges asked lawyers for the House and the Justice Department whether their positions had changed following the vote to impeach Trump on Dec. 18. The judges in each case asked “whether the articles of impeachment render this case moot and whether expedited consideration remains necessary.” The lawyers were also asked to address whether lawmakers are seeking McGahn’s testimony and the grand jury evidence in connection to the impeachment inquiry — or to legislative oversight.
Joseph Ellis, a Pulitzer Prize-winning historian, seems to share the Democrats' view. He recently wrote a CNN op-ed titled "Pelosi should block impeachment trial until White House is forced to reveal all":
Let's call it the Pelosi Pause. There are no written rules governing the timetable for delivery of the House decision impeaching Donald Trump to the Senate, only custom. But then there were no written rules governing the timetable for a Senate decision on Barack Obama's nomination of Merrick Garland, only custom. If Speaker Nancy Pelosi follows Senator Mitch McConnell's playbook, Donald Trump will never stand trial in the Senate.
From a Democratic perspective that outcome would be preferable to a show trial, where the conclusion is not just foreordained, but announced beforehand by the Majority Leader after consulting with White House counsel. It's perfect: a rigged trial of a President accused of plotting a rigged election. We can only assume that Senator McConnell will be winking at the camera when he takes the oath of impartiality, "so help me God."
Pelosi need not wink, she only needs to wait. How long? Until November 2020, if necessary. McConnell claims that he has all the leverage because he has the votes in the Senate, and that, not the evidence described in the impeachment report, is all that counts. But it counts for nothing until the Senate receives the impeachment recommendation from the House.
Ellis suggests Pelosi might be holding a stronger hand of cards than does McConnell:
This is what Speaker Pelosi knows, and that could be why she is waiting. One could argue, and presumably pragmatic colleagues may be urging this course, that Pelosi and Senator Schumer should negotiate the best deal they can get and trust that some vestigial residue of bipartisanship still lingers in a few Republican senators, who might force McConnell to conduct a fair trial.
Dream on, Macduff. The Republican performance in the House impeachment proceedings made crystal clear that there is no Republican Party, only the Trump Party, which conducts itself according to Trumpian standards of civility and statesmanship, meaning like trained seals. Trusting in bipartisanship in McConnell's Senate is a surrender strategy.
Ellis has ideas about the course Democrats should follow, and we like his thinking:
Let me propose an alternative course for Pelosi. Apprise McConnell that she will forward the impeachment recommendation as soon as the Supreme Court rules on the three cases currently pending in the lower courts concerning the president's refusal to provide the documents and witnesses requested by the House Intelligence Committee and the tax returns requested by the Ways and Means Committee. The Supreme Court has already agreed to take the latter case. Chief Justice John Roberts can be urged to accelerate the schedule in all three cases, and report the verdicts prior to the customary end of the Supreme Court session in June.
In all three cases, White House lawyers have made the same argument; namely that the President has the constitutional authority to ignore all congressional requests, because he cannot be indicted, convicted, or investigated. In brief, as President he stands above the law. All the lower court rulings thus far have dismissed this argument as frivolous. Perhaps the cases can be bundled and decided by the Supreme Court sooner rather than later.
If the decision follows the precedent set in Nixon v. United States (1974), where the Supreme Court ruled, quite quickly, that Nixon had to release the White House tapes, then witnesses and documents unavailable to the House will become available for a Senate trial. Polls indicate that a majority of Americans prefer a full and fair trial that includes such testimony and evidence. If McConnell refuses to yield to the political process that generates, Pelosi can stand pat until he caves. If never, so be it. It must be a full and fair trial or nothing.