Hillary Clinton’s running mate, Sen. Tim Kaine of Virginia, made an unexpected stop at the campaign’s Portland headquarters on his way to a fundraiser Thursday night.

The impromptu visit came as recent national polls show the Democratic presidential candidate’s lead over Republican Donald Trump shrinking.

In a two-way match-up, a CBS News/New York Times poll released Thursday gave Clinton a slight edge over Trump, 46 percent to 44 percent among likely voters who support or lean toward a candidate, CBS News reported. In a four-way race, the poll had the candidates in a statistical tie.

Other polls had Trump leading in some critical battleground states such as Florida and Ohio.

A Colby College poll released this week showed the race between Clinton and Trump narrowing in Maine, increasing the likelihood that the Republican could win at least one of the state’s electoral votes in November.

The poll, conducted last week by SurveyUSA, had Clinton leading Trump 42 percent to 39 percent in Maine with less than eight weeks until Election Day. That falls within the poll’s margin of error of 3.5 percentage points.

Kaine alluded to the polls Thursday night.

“We’re going to have close races all over this country,” Kaine told volunteers in Portland.

“Because of the way you guys do electoral votes, the (Second District) race is really important, obviously not just to win in Congress, but to win the electoral votes” the campaign needs to win the presidency, Kaine said.

About a dozen Portland volunteers were surprised Thursday when camera crews, campaign staff and Secret Service agents started filling their phone bank in a small basement room of a Congress Street building.

John George, 63, from Limington, said he has volunteered at the phone bank every day since January.

He had just finished his 120 calls and was getting ready to leave, but a staffer told him to stay. Moments later, Kaine’s entourage filled the space.

“It was very unexpected,” George said, just after Kaine left the room. “Wow!” he exclaimed, pumping his arms in the air.

Kaine planned no public appearances in Maine, according to the Clinton campaign. Clinton’s Maine campaign staff told the press about his appearance Wednesday. This is Kaine’s first visit to Maine as a vice presidential candidate. Hillary Clinton made a campaign stop in Portland a year ago.

Trump has made three stops in Maine this year, including two rallies in Portland, and the most recent in August.

Kaine landed in a campaign plane in Portland at 5:25 p.m. and he was greeted by several Maine Democrats, including 1st District Rep. Chellie Pingree, Maine Speaker of the House Mark Eves, Portland Mayor Ethan Strimling and state Sen. Anne Haskell of Westbrook. Strimling snapped a selfie with Kaine.

A motorcade whisked campaign staff, national and local press and security to the campaign office.

Kaine did not answer questions from the press.

Inside, the vice presidential candidate made three phone calls to Portland-area volunteers. In remarks to the room, he juxtaposed Clinton’s book “Stronger Together” to Trump’s “Crippled America.”

“I do not see anything in this country as I travel around with Americans every day that resembles the America that Donald Trump is describing,” Kaine said.

Clinton’s plan to provide debt relief from student loans and make tuition free for families earning up to $125,000 a year is “the centerpiece of our higher education agenda,” Kaine said.

“Donald Trump, the only thing we know about his higher ed agenda is Trump University,” Kaine said, referencing a for-profit college founded by the Republican candidate that is being sued by the New York attorney general on fraud allegations.

Kaine also hit Trump on his plan, released this week, to guarantee six weeks of paid maternity leave for new mothers.

That proposal is basically an unemployment benefit available only to women, Kaine said. Clinton’s plan would give 12 weeks of paid family leave to men and women to take care of a sick child or family member or recover from serious illness or injury, Kaine said.

Kaine also cited a recently publicized Newsweek report that questioned how Trump’s many foreign business interests could complicate American foreign security if he became president.

Aside from questions about conflict of interest, the report called into question Trump’s priorities, Kaine said.

“I don’t want a president who thinks of his own bottom line, I want a president who thinks of Maine’s bottom line, of Virginia’s bottom line, of America’s bottom line.”

Kaine spoke for about 15 minutes, then headed to the home of Bonnie Porta and Bobby Monks in Cape Elizabeth, where guests paid $1,000 to $2,700 to attend.