Tax reform is not health-care reform – not in substance, not in politics, and not in the White House wooing of Republican Sen. Susan Collins of Maine, one of three swing votes that blocked her party’s plan to repeal and replace Obamacare in July.

Unlike last summer, Senator Collins has met three times with President Trump to talk taxes, and has gotten personal commitments from him on key measures in an effort to get her to “yes.”

“There has been so much more outreach,” Collins said Thursday at a breakfast for reporters hosted by The Christian Science Monitor, as the Senate debated what could become the biggest tax-code overhaul since 1986. “It’s just night and day compared to the health bill.”

Not only has the president paid her more mind, but so have White House officials and Senate leaders in her party. That shows her clout as a moderate Republican in a narrowly divided chamber, on an issue that instead of taking away a benefit attempts to revamp a tax code Americans dislike. Republicans consider the tax overhaul a must in a year of few legislative achievements for them.

Just before Thanksgiving, she and two other Republican senators went to the White House. Collins says she showed the president a chart to make her case that if Congress went ahead with his wishes and dropped Obamacare's individual insurance mandate as part of the GOP tax plan, then rising health-plan premiums would cancel out the tax cuts for some middle-income taxpayers.

“He was obviously concerned about that,” she said of Mr. Trump. She met with him again privately on Tuesday in advance of the weekly party luncheon at the Capitol, where he backed two of her big asks: support for a bipartisan bill to help offset insurance premium increases and another one to give states funds to set up “high-risk” insurance pools, also meant to keep a lid on premiums.

The president was also supportive of her aim to match the House bill by allowing a deduction of up to $10,000 on property taxes – a concern in high-tax states.

But, like some other GOP senators, she’s not a firm "yes" yet. She has other items on her wish list, including making a tax credit for child and adult dependent care refundable and keeping the top tax rate at 39.6 percent for millionaire filers. Collins sees no problem with a corporate tax rate of 21 percent, instead of the 20 percent in the House bill, as an offset – and indeed, other Republican senators also see a slightly higher corporate rate as a way to be more generous toward middle- and low-income earners.

The senator said she has pressed CEOs of large corporations with plants in Maine, and with one exception all said they would be “delighted” with a 22 percent rate.

Still, she held firm to her red lines as the Senate seeks to finalize its bill, with a vote expected by the end of the week. Both the property-tax deduction and health-care legislation are “extremely” important, she said. “It would be very difficult for me to support the bill if I do not prevail on these two issues.”

In response to other questions at the breakfast, she said that her recent conversations with the president have given her “no reason to be concerned” about his mental health, though she says it’s not helpful when he raises “conspiracy theories” or puts out tweets of anti-Muslim videos “that are not accurate.”

She also said that Congress needs to resolve the “Dreamers” issue before the end of the year, so that young people who came to the US as children of unauthorized immigrants can stop living in fear. “It is imperative that we act,” she said, though she is not willing to block a government spending bill to force the issue, as some Democrats want.