ROCHESTER, Mich. (Reuters) - Democratic Representative Elissa Slotkin, co-author of a column that helped launch the impeachment inquiry of President Donald Trump, ended months of uncertainty on Monday by telling voters at a noisy town hall meeting that she will vote for impeachment.

The cheers - along with chants of “Impeach Slotkin, keep Trump!” - that greeted her decision underlined the wrenching partisan pressures that vulnerable Democrats in swing districts have faced ahead of this week’s planned House vote on impeaching the Republican president.

“To me, this is something that I cannot abide,” Slotkin, a former CIA and Department of Defense official who captured a Republican-held seat in 2018, said of charges that Trump abused his power to pressure Ukraine to investigate political rival Joe Biden and obstructed Congress’ probe of the matter.

Slotkin is one of seven first-term House Democrats with national security backgrounds who helped pave the way for the impeachment inquiry of Trump, writing a column in the Washington Post in September backing the probe and calling the Ukraine scandal “a threat to all we have sworn to protect.”

The call by the seven lawmakers, who all captured Republican-held districts in 2018, signaled a broader shift toward impeachment by Democrats after the Ukraine allegations surfaced. House Speaker Nancy Pelosi opened the inquiry shortly afterward.

Slotkin and the other authors of the column, along with dozens of other moderate Democrats from competitive districts, have come under heavy pressure as the impeachment vote approaches, facing millions of dollars in ads from outside conservative groups and a flood of phone calls from voters.

Two other co-authors, Representatives Abigail Spanberger of Virginia and Jason Crow of Colorado, announced their support for impeachment. “Today I am driven by facts and evidence to protect the integrity of our democracy,” Spanberger, another CIA veteran, tweeted on Monday.

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At the packed town hall in Slotkin’s Republican-leaning southeastern Michigan district, which Trump carried in 2016 by nearly 7 percentage points, most of the audience of about 500 cheered Slotkin’s announcement she would back impeachment. But a crowd of protesters chanted and shouted for nearly the entire hour-long event, sometimes drowning out her comments.

“You may just want to listen for one second,” Slotkin addressed the protesters directly at one point, trying to answer questions through the shouts.

The pro-Trump attendees said Slotkin was following Democratic Party marching orders and making a political miscalculation.

‘A POLITICAL DISASTER’

“This decision is going to be a political disaster for her,” said Matt Maddock, a Republican state lawmaker in Michigan who joined the protesters.

Trump denies wrongdoing and he and his Republican allies accuse Democrats of a baseless and politically motivated bid to oust him from power.

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Slotkin told reporters after the town hall she was not concerned about predictions she would pay for the decision at the ballot box in 2020.

“There just have to be some decisions that are beyond the political calculus,” Slotkin said.

Republican and conservative groups have cranked up the pressure on the column authors, along with dozens of other Democrats in swing districts, ahead of the full House vote on impeachment later this week.

The American Action Network, a conservative advocacy group that opposes impeachment, is spending $1.5 million on television ads in 10 congressional districts, including Slotkin’s, on top of an earlier $7 million outlay across three dozen districts.

America First Policies, a pro-Trump political action group, launched a $2.2 million pressure campaign featuring television, digital and newspaper ads, urging voters to contact Democrats in 27 House districts won by Trump in 2016, including Slotkin, and tell them “to end the witch hunt.”

Slotkin said last week she added another phone line in her office to handle the flood of calls, and noted on Monday she had received more than 1,500 phone calls and 6,500 emails and letters on the subject since her column.

She told reporters she spent the weekend quietly reviewing the facts and had not faced any pressure from Democratic House leaders.

“I haven’t felt pressure from my leadership at all,” she said. “I do believe we live in a world where there are still facts, where there is still data, where there are still rules, and there are still standards.”