With Senate passage of the tax-cut bill, it looks very likely that President Trump and Republicans will finally get one of their top priorities enacted into law. The big question is whether the legislative win is also a political win.

Though what comes out of a House-Senate conference committee can’t be known unless the House simply adopts the Senate version of the bill, the impact of the resulting tax bill could be both good and bad politics. Republicans have convinced themselves of the necessity of passing a tax bill to demonstrate their competence and make good on a promise to their base.

Republicans and conservatives have grown increasingly frustrated with the lack of major legislative accomplishments this year, particularly their inability to repeal and replace Obamacare, something that many of them felt they would do without breaking a sweat. Consequently, passage of the tax bill is seen as critical to getting GOP voters to cast their ballots in next November’s midterm elections, which would make the bill good politics. With midterm turnout about 40 percent less than in presidential years, getting out the party’s base is extremely important.

But given the myriad of polling data showing widespread unpopularity of the tax legislation among independents and Democrats—in other words, everyone outside of the GOP base—it could be bad politics. Moderate and independent voters in the ideological and partisan middle clearly don’t like what they’ve heard about the bill, and few are inclined to give Trump or congressional Republicans the benefit of the doubt. Their measured opposition, along with the strong hostility of Democrats and liberals, promises to create a steep hill for Republicans in the midterms.

One constant in recent years has been the Republicans’ preoccupation with their base, an all-consuming focus on placating their die-hard supporters regardless of the feelings of people who are not among the party faithful. The political math argues against this strategy: Hard-core Republicans and conservatives constitute only about a third of the electorate, and their views often aggravate the two-thirds outside their circle.

Last year, 77,744 votes scattered across Michigan (10,704), Pennsylvania (44,292), and Wisconsin (22,748) enabled Donald Trump and Republicans to capture the White House despite an overall deficit of almost 2.9 million votes nationwide. The enthusiasm and intensity within the Republican Party and Trump’s base outweighed the ambivalence and complacency prevalent among Democrats and voters on the Left.

Can Republicans count on pulling that off again in 2018? The answer is probably yes in the upper chamber. Trump carried 10 states that have Democratic senators facing reelection next year, plus two other potentially important states (Arizona and Tennessee, the latter of which would be competitive in 2018 only if former Democratic Gov. Phil Bredesen runs), leaving only one Republican, Sen. Dean Heller of Nevada, up for election in a state where Hillary Clinton prevailed.

But in the House, where Democrats need a gain of 24 seats and with Clinton having won 23 seats that are held by the GOP, this base-oriented strategy is less compelling. The danger for Republicans is that the intensity in politics today seems to be far greater on the Democratic side than it is on their own, and they are marginalizing themselves among the swing voters in the middle.

Democrats, however, have their own base politics potentially getting in the way. To the consternation of their congressional leadership, there is considerable talk within the base and with a small but highly vocal number of Democrats in Congress about impeachment, which would involve charging Trump with obstruction of justice.

Let’s assume that Democrats win a House majority, which today looks like a 50-50 proposition. Given that a simple majority is needed in the House to pass articles of impeachment, it is a plausible course of action, though I think it highly unlikely. But even if Democrats did manage to impeach Trump in the House, a two-thirds majority in the Senate would be necessary to convict him and remove him from office. Democrats, who currently have 48 Senate seats, would need to win the Alabama special election on Dec. 12, hold all 25 of their own Senate seats up next year including the 10 in states Trump carried, then capture all nine GOP seats that are up—in other words, win every single one of the 34 Senate races next year (a virtual impossibility).

That would give them 58 Senate seats, still nine short of the number required to win a conviction on a party-line vote. They would need nine Republican senators to swing their way and vote to remove Trump, who currently has an 81 percent job approval rating among self-identified Republicans. By my math, the chances of that happening are zero, with a margin of error of zero.

This story was originally published on nationaljournal.com on December 5, 2017