Multiple polls have now shown that some 70% of Americans want to see witnesses at the Senate trial, including about 50% of Republicans. The new CNN/SSRS poll this week found that 69% of the public say the Senate impeachment trial beginning Tuesday should include testimony from new witnesses, including 48% of Republicans. The finding is nearly identical to an ABC/Washington Post poll last month that found 71% of respondents think Donald Trump should let his top lieutenants testify, including 64% of self-identified Republicans.
Arguing about process on Capitol Hill is usually pretty useless because it tends to move voters much less than actual outcomes do. One good example is the fact that Majority Leader Mitch McConnell completely ignored his constitutional duty (i.e. upended normal process) when he refused to even give President Obama's Supreme Court nominee Merrick Garland a hearing. Republicans never paid a price for that at the ballot box in 2016. But Republican voters likely largely backed the move because it gave them an opportunity to deny Democrats a major win on the Supreme Court.
In this case, however, more Republican voters want to see witnesses than don't, not to mention the vast majorities of Democrats and Independents. The support among GOP voters is likely partly a product of House Republicans continually complaining that the House inquiry only included 2nd-, 3rd-, and 4th-hand witnesses—which was actually true but precisely because Trump had blocked all the 1st-hand witnesses like former national security adviser John Bolton or acting chief of staff Mick Mulvaney, who's neck deep in this Ukraine scandal. Many Republican voters likely also believe the bogus GOP talking point that the House inquiry both prohibited Republicans from calling witnesses and excluded Trump's lawyers from making their case altogether. Neither are true in the least—America absolutely heard from GOP witnesses and the White House chose not to have Trump's lawyers participate. Nonetheless, many Republican voters out there probably see the Senate trial as a place where Trump can finally exonerate himself through testimony and evidence. Only he can't because he's so damned guilty.
But the main point is, 60+% of Americans rarely agree on much anything happening on Capitol Hill, so 70% agreement among the public is almost an unprecedented amount of support for process-y matter that in most cases would be overlooked. Not this time. The desire among Americans is obvious, and McConnell short-circuiting the process to exclude any witness testimony will be just as obvious.
As Nicolle Wallace said on MSNBC Tuesday morning, "Mitch McConnell is playing with lit matches when he plays these process games today."
Former RNC chair Michael Steele also noted on MSNBC that Republicans appear to really be playing the short-game here to save the president, while leaving the long-game of November for another day. Steele doesn't think it's smart, noting that if 71% of Americans say they want witnesses and documents and 51% say they want Trump removed from office, "that's a long-term problem that you need to mitigate right now and you don't mitigate that through process, you've got to mitigate that with some level of substance because, substantively, the American people have looked at this and come to the conclusion, 'I need to see more and what I've seen so far is enough for me to say, you got to go.'"
And in fact, there's a solid swath of Republicans who don't yet support removal but have decided they need more witnesses and evidence in order to support acquittal. As Steele pointed out, Trump is accused of trying to cheat in order to win 2020 and now McConnell is trying to cheat in order to get him off.