Meanwhile, there is an underlying fact that's hard to ignore: almost six months into his presidency, he hasn't had a single major legislative accomplishment.
Senators will question Comey on whether Trump tried to get him to back off an FBI investigation into ties between the president's 2016 campaign and Russian Federation, an attempt that critics have said could constitute obstruction of justice. "We've already lost [Sen.] Rand Paul [R-Ky.], so we're down to 51". John Kennedy said Tuesday that costs are growing out of control and adding more money to Medicaid is "like adding paint to rotten wood".
That led to a lawsuit which is working its slow way through the courts - but which the Trump White House could abandon at any time.
And essentially every Hill Republican was elected on a promise to repeal and replace ObamaCare.
"There's no doubt that keeping members focused on investigations detracts from our legislative agenda, detracts from what we're trying to deliver for the American people", Marc Short, Trump's legislative affairs director, told reporters Monday night.
"In all honesty, I think it's a stalled Congress", Sen. GOP senators shuffling in and out of closed door meetings have mostly been tight-lipped about what deals are being hashed out, and Tuesday was no exception.
"Well we've had plenty of time to discuss this issue as I've pointed out before - since there are a fewer number of us", McConnell said.
Repealing and replacing the Affordable Care Act is the centerpiece of Trump's legislative agenda, but congressional Republicans have been unable to coalesce around a suitable plan to do so.
House Republican leaders are asking senators to agree to remove more than $150 million they want to spend in Louisiana's budget next year, the House's initial offer in negotiations over a final version of the $28 billion-plus spending plan ahead of Thursday's end of the legislative session. The CBO must issue a score on the bill, detailing how much it would cost and how many individuals would lose coverage, before the chamber can hold a vote.
"There should be", Republican Sen. Ted Cruz of Texas, praise this strategy.
"One of the most encouraging aspects of these discussions is they have not been litigated in the press", he said.
But others say a more open process, including one that didn't rely on a procedural maneuver that will allow simple majority passage without any need to build bipartisan consensus with Democratic votes, would have been more productive.
Sen. Roy Blunt said, "My personal view is we've got until about the Fourth of July to decide whether the votes are there or not and I hope they are".
Republicans are expected to be presented with a menu of options to overhaul Obamacare. "I think it's our responsibility". All this means that congressional Republicans face the possibility of having done nothing of outcome by September 30, the end of their first fiscal year in power.
And although premiums may go down for some people, premiums and out-of-pocket expenses will increase significantly for many others, especially those who are older and those with pre-existing conditions. "Cory Booker of New Jersey and Kamala Harris of California, have signaled support for some version of universal government care". Shelley Moore Capito (R-W.Va.), whose state greatly benefits from the Medicaid expansion, and Dean Heller (R-Nev.), who is up for a tough re-election contest in 2018.
Medicaid was expanded under Obamacare but the House bill would phase that expansion out in 2020.
If McConnell can not bridge the Medicaid divide, he may have to refocus efforts on more limited legislation to rescue insurance markets across the country that have been battered by the political turmoil in Washington.
U.S. President Donald Trump said on Wednesday that the Obamacare healthcare system is in a "death spiral" and must be reformed soon, a day after insurer Anthem Inc announced it would withdraw from the OH healthcare insurance exchange next year.
On Tuesday, Anthem announced it was pulling out of Ohio's Obamacare marketplace, leaving thousands without coverage on the private market.
House Minority Leader Nancy Pelosi said Tuesday that Trump was "sabotaging" the health care law.