Two more former “Hillary for president” backers are getting a campaign visit from President Clinton.

They are Rep. Sandy Levin (D-Mich.) and congressional candidate John Callahan (D-Pa).

Levin faces a Democratic primary challenge on Aug. 3 from state Sen. Michael Switalski. Clinton will headline a fundraiser next week for the 14-term congressman, who backed Secretary of State Hillary Rodham Clinton during her 2008 primary campaign.  

On Aug. 10, the former president travels to Pennsylvania to raise money for Bethlehem Mayor John Callahan, who is challenging Rep. Charlie Dent (R). 

Callahan, whose campaign manager did advance work for the Clinton White House, was a Hillary ClintonHillary Rodham ClintonOJ Simpson knocks Trump out of the cable news spotlight Poll: Women paying more attention to politics since Trump’s election Poll: Nearly half of liberals say friend supporting Trump would hurt friendship MORE backer all the way through Pennsylvania’s Democratic primary in March of ’08. 

The former president has proved a popular figure on the campaign trail this year. A recent Gallup poll showed he is more popular than President Obama.

Clinton has campaigned for other politicians who supported his wife. Most notably, the former president endorsed Andrew Romanoff in the Colorado Democratic Senate primary. Romanoff is challenging sitting Sen. Michael BennetMichael BennetTax credits bring much needed relief Senate Dem: No clarity, 'little competence' behind travel ban Dems step up attacks on GOP ObamaCare bill MORE (D-Colo.) and supported Hillary Clinton in 2008.

There is also talk Clinton will head to Florida in August to campaign for Rep. Kendrick Meek (D-Fla.), who's running for Senate and is another Hillary Clinton supporter.

-- This post was updated at 11:29 a.m. and corrected at 12:20. It incorrectly reported that Callahan had done advance work for the Clinton White House.