Nonprofit leaders worry that doubling the standard deduction would remove the tax incentive for a big chunk of annual charitable giving:

http://www.thenonprofittimes.com/news-articles/tax-plan-doubles-standard-deduction-leaves-charitable-deduction-place/

http://www.thenonprofittimes.com/news-articles/opinion-enhanced-incentives-charitable-giving-make-good-tax-policy/