LONDON — Democrats in the United States often wonder why more Republicans don’t speak out against President Trump. They could learn a lot from the sad, cautionary tale of Britain’s David Gauke.

Gauke was once a Conservative Party rising star. A member of Parliament from a safe, affluent, suburban London seat, Gauke rose quickly once the Tories came to power in 2010. He was appointed to a series of junior ministerial positions in Prime Minister David Cameron’s cabinet and became a senior member of Prime Minister Theresa May’s cabinet in 2017. Since he was only in his mid-40s, a long and potentially powerful career lay in front of him.

But Gauke was not a Brexiteer. He loyally backed May’s Brexit deal in Parliament, but hard-line Tory Brexiteers rebelled and shot it down. That failure led to the collapse of Tory support in this year’s European Union election as Nigel Farage’s new Brexit Party swept to victory. Polls in mid-summer showed the Tories in fourth place with less than 20 percent of the vote as their supporters flocked to Farage. May stepped down as the Tory leader, and the Brexiteer party majority elected the hero of the pro-Brexit referendum campaign, former London mayor Boris Johnson, to replace her.

That was the last straw for Gauke. He resigned from the cabinet after Johnson’s election, saying that he could not support the possibility of leaving the European Union without a deal that would secure Britain’s economic strength. He then joined with other like-minded Tory rebels to back efforts by the opposition to seize control of Parliament from Johnson rather than risk a no-deal Brexit. Gauke lost the Tory Party whip as a result, effectively removing him from the party.

Others who lost the whip made up with Johnson and returned to the party, but Gauke persisted. A man of principle, he could not countenance the economic disruption he believes will ensue from a no-deal Brexit. He set forth his views eloquently in the important Tory blog, Conservative Home, in November. Tories like him were “pro-business,” “cautious about public finances" and “worried about a No Deal Brexit." Not a socialist like Labour Party’s Jeremy Corbyn and not pro-Remain enough to become a Liberal Democrat, Gauke — and the hypothetical Tory voter he described — were in a pickle about whom to vote for.

Gauke decided to stand for reelection as an independent in his constituency of South West Hertfordshire. He seems to be a perfect fit for a wealthy, perennially Tory seat that voted to stay in the E.U. Instead, he is tipped to lose by a wide margin next week.

It’s not hard to see why. Most Tory voters were either staunchly pro-Brexit or can’t stand the thought of a socialist prime minister, so they are voting for the party that will back their values or keep them safe. And because he isn’t left-wing or pro-Remain enough, the other anti-Brexit parties won’t support Gauke, even though he is the only person with enough crossover appeal to beat the Conservatives. Like many traditional Republicans, Gauke is caught between a populist right he cannot abide and a left he cannot support. And there aren’t enough people like him to make an independent stand.

This fact means most voters must choose between Conservatives and Labour, and Johnson is ruthlessly exploiting their justified fears. The Conservative campaign is attacking Labour’s manifesto as a scheme to spend trillions and raise taxes by an average of more than 2,000 pounds per household. The campaign is working, as Lord Ashcroft’s polls find that the vast majority of 2017 Conservative voters who also oppose Brexit are backing the Tories again and think a Labour government would be worse than leaving the E.U.

There’s a lesson in this for Democrats: Republican officeholders might have doubts about Trump, but they won’t oppose the vast majority of their voters who don’t by backing impeachment. The Democrats’ move to left also scares those former Republicans whose votes will decide the 2020 race. Just as Tory Remainers grudgingly prefer Johnson and Brexit to Corbyn and socialism, moderate Republicans could prefer Trump’s circus to Elizabeth Warren’s or Bernie Sanders’s class warfare.

There’s also a lesson here for Trump: Johnson isn’t playing only to his base of conservative Brexiteers. He’s reaching out to former Labour voters who have never voted Conservative before with tax and spending plans designed to appeal to them. He’s reaching out to Tory Remainers by pointing out the unpalatable alternatives and pledging not to hike income taxes or the national sales tax. If he wins, it will be because he is building a coalition, not just rallying his partisans.

Millions of David Gaukes live in the United States’ suburbs. The party that best understands their conflicted politics will take a big step toward victory next November.

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