More than 400,000 students headed back to Chicago public schools today, and many had politicians on hand to welcome them to class.

The time-honored tradition of officials ringing school bells on the first day of the year takes on added importance for them heading into election campaigns — as they seek support and to highlight their education work — and this year is no exception.

Mayor Rahm Emanuel isn't under as much scrutiny as he was on the first day of school in 2013, when students were starting classes for the first time since the mayor closed dozens of public schools and many parents were complaining their children were going to have to commute through dangerous neighborhoods to new schools.

And unlike in 2012, there's no teachers strike. But a recent Tribune poll found nearly two-thirds of Chicago voters disapprove of the mayor's handling of the public schools.

The mayor has in recent weeks touted reports showing improved Chicago public high school graduation rates and ACT scores as evidence his policies are working.

Emanuel was set to turn up Tuesday for the opening bell at Penn Elementary School in the Lawndale neighborhood, one of the schools that will get a Safe Passage route this year. He was also set to talk to students at dismissal, but hadn't announced which school he would visit at the end of the day.

Last year, Safe Passage workers set up around schools that would welcome students from the closed schools to try to make sure they got there safely. The city earmarked $1 million to expand Safe Passage to additional schools this year, and Gov. Pat Quinn kicked in another $10 million in state money to increase the size of the program.

Quinn, himself seeking re-election, was scheduled to welcome students at Vanderpoel Elementary School in Beverly. He then was slated to head to Schmid Elementary School in the Cottage Grove Heights neighborhood to talk to students in classrooms.

Chicago Teachers Union President Karen Lewis continues to mull a run against Emanuel. As part of her ongoing criticism of the mayor's education policies, Lewis on Tuesday was to go to Dyett High School in Bronzeville. The Chicago School Board voted to phase out Dyett by the end of this school year, and Lewis wants to draw attention to why she believes it should stay open.

Other teachers union officials will head to other public schools.

jebyrne@chicagotribune.com