Franklin Pierce, a Democrat, succeeded Millard Fillmore as President in 1853. Pierce took office after the Whig party, to which Fillmore belonged, faced internal divisions and failed to nominate Fillmore for the presidency in 1852. As for Pierce's thoughts on Fillmore's administration, it's essential to note that political dynamics can be complex, and individual opinions may vary. Pierce likely had his own views on Fillmore's policies, but concrete details about his specific opinions aren't as well-documented as his actions during his own presidency. If you have a more specific aspect or event in mind, feel free to ask for further clarification.